This project will design next-generation defense mechanisms to protect critical infrastructures, such as power grids, large industrial plants, and water distribution systems. These critical infrastructures are complex primarily due to the integration of cyber and physical components, the presence of high-order behaviors and functions, and an intricate and large interconnection pattern. Malicious attackers can exploit the complexity of the infrastructure, and compromise a system's functionality through cyber attacks (that is hacking into the computation and communication systems) and/or physical attacks (tampering with the actuators, sensors and the control system). This work will develop mathematical models of critical infrastructures and attacks, develop intelligent control-theoretic security mechanisms, and validate the findings on an industry-accredited simulation platform. This project will directly impact national security and economic competitiveness, and the results will be available and useful to utility companies. To accompany the scientific advances, the investigators will also engage in educational efforts to bring this research to the classroom at UCR, and will disseminate their results via scientific publications. The work will also create several opportunities for undergraduate and graduate students to engage in research at UCR, one of the nation's most ethnically diverse research-intensive institutions. This study encompasses theoretical, computational, and experimental research at UCR aimed at characterizing vulnerabilities of complex cyber-physical systems, with a focus on electric power networks, and control-theoretic defense mechanisms to ensure protection and graceful performance degradation against accidental faults and malicious attacks. This project proposes a transformative approach to cyber-physical security, which builds on a unified control-theoretic framework to model cyber-physical systems, attacks, and defense strategies. This project will undertake three main research initiatives ranging from fundamental scientific and engineering research to analysis using industry-accepted simulation tools: (1) modeling and analysis of cyber-physical attacks, and their impact on system stability and performance; (2) design of monitors to reveal and distinguish between accidental and malignant contingencies; and (3) synthesis of adaptive defense strategies for stochastic and highly dynamic cyber-physical systems. Results will first be characterized from a pure control-theoretic perspective with focus on stochastic, switching, and dynamic cyber-physical systems, so as to highlight fundamental research challenges, and then specialized for the case of smart grid, so as to clarify the implementation of monitors, attacks, and defense strategies. The findings and strategies will be validated for the case of power networks by using the RTDS simulation system, which is an industry-accredited tool for real-time tests of dynamic behavior, faults, attacks, monitoring systems, and defensive strategies.

Intellectual Merit: Recent developments in nanostructures manufacturing, sensing and wireless networking, will soon enable us to deploy Flow-based Cyber-Physical Systems equipped with sensing and actuation capabilities for a broad range of applications. Some of these applications will be safety critical, including water distribution monitoring (i.e., critical national infrastructure systems particularly vulnerable to a variety of attacks, including contamination with deadly agents) and interventional medicine (i.e., a medical branch that makes use of tiny devices introduced in a living body through small incisions, to detect and treat diseases). The goal of this project is to advance our fundamental understanding, through a robust mathematical framework, of emerging field of Flow-based Cyber-Physical System. The project develops new architectures, models, metrics, algorithms and protocols for optimal sensing, communication and actuation in Flow-based Cyber-Physical System deployed on-demand (i.e., reactively, when sensing and actuation is needed) or proactively. Flow-based Cyber Physical Systems consist of mobile sensor nodes and static nodes, aware of their location. For stringent requirements (e.g., form factor, cost, energy budget) nodes may or may not possess node-to-node communication capabilities. Due to the lack of localization infrastructure, mobile sensor nodes infer their location only by proximity to static nodes. Sensor nodes are moved by the flow in the network, detect events of interest and proximity to static nodes, communicate and actuate. This research will enable, for example, water distribution monitoring systems to accurately and timely detect events of interest in the infrastructure and to react to these events. It may enable doctors to detect diseases and deliver medication with microscopic precision. Broader Impacts: Ultimately, the outcomes of this research will have impact on CPS that operate in critical modes and environments and control critical infrastructures and medical applications. The results from this research may also foster new research directions in CPS applications. The PI will integrate the research results in newly approved courses on CPS at Texas A&M and disseminate course materials online through the project website and Rice University Connections Consortium. This project will also offer research opportunities to undergraduate students, underrepresented groups, and high school students participating in the Texas Science Olympiad and National Science Olympiad.

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.

The objective of this research is to understand the loosely coupled networked control systems and to address the scientific and technological challenges that arise in their development and operation. The approach is to (1) develop a mathematical abstraction of the CPS, and an online actuation decision model that takes into account temporal and spatial dependencies among actions; (2) develop algorithms and policies to effectively manage the system and optimize its performance with respect to applications' QoS requirements; and (3) develop an agent-based event-driven framework to facilitate engineers easily monitor, (re)configure and control the system to achieve optimized results. The developed methodologies, algorithms, protocols and frameworks will be evaluated on testbeds and by our collaborating institution. The project provides fundamental understanding of loosely coupled networked control systems and a set of strategies in managing such systems. The components developed under this project enables the use of wireless-sensor-actuator networks for control systems found in a variety of disciplines and benefits waterway systems, air/ground transportation systems, power grid transmission systems, and the sort. The impact of this project is broadened through collaborations with our collaborating institution. This project provides a set of strategies and tools to help them meet the new standards. The inter-disciplinary labs and curriculum development at both undergraduate and graduate level with an emphasis on CPS interdisciplinary applications, theoretical foundations, and CPS implementations prepare our students as future workforce in the area of CPS applications.

The objective of this research is the transformation from static sensing into mobile, actuated sensing in dynamic environments, with a focus on sensing in tidally forced rivers. The approach is to develop inverse modeling techniques to sense the environment, coordination algorithms to distribute sensors spatially, and software that uses the sensed environmental data to enable these coordination algorithms to adapt to new sensed conditions. This work relies on the concurrent sensing of the environment and actuation of those sensors based on sensed data. Sensing the environment is approached as a two-layer optimization problem. Since mobile sensors in dynamic environments may move even when not actuated, sensor coordination and actuation algorithms must maintain connectivity for the sensors while ensuring those sensors are appropriately located. The algorithms and software developed consider the time scales of the sensed environment, as well as the motion capabilities of the mobile sensors. This closes the loop from sensing of the environment to actuation of the devices that perform that sensing. This work is addresses a challenging problem: the management of clean water resources. Tidally forced rivers are critical elements in the water supply for millions of Californians. By involving students from underrepresented groups, this research provides a valuable opportunity for students to develop an interest in engineering and to learn first hand about the role of science and engineering in addressing environmental issues.