This project envisions mobile cyber-physical systems (CPS) where people carrying cell phones generate large amounts of location information that is used to sense, compute and monitor human interactions with the physical environment during environmental dislocations. The main objective will be to identify the types of reactions populations have to a given type of shock, providing decision makers with accurate and informative data-driven representations they can use to create preparedness and response plans. Additionally, the outcomes of this project will allow for the development of tools to assess and improve the effectiveness of different types of preparedness and response policies through feedback loops in the mobile CPS. These feedback loops could show how community behaviors during shocks change when policies are re-defined based on the computations of the CPS, and vice-versa. Previous work by the PI and others has already showed that CPS integrating people and cell phones as sensing platforms can be used to collect location information at large scale and to compute, using data mining and machine learning techniques, human mobility behaviors during shocks. However, most of the results are very limited and ad-hoc, lacking any type of serious applicability from a preparedness and response policy. This project will advance the state of the art by developing accurate methods and effective tools for decision-making during shocks in mobile CPS. From a broader impacts perspective, the proposed research will contribute in two areas: (a) real-world deployments, to promote data-driven policy development, data-driven analyses of human behavior, and the use of feedback loops in mobile CPS for decision-making assessment; and (b) the creation of an educational plan and training opportunities in the areas of data science for social good and mobile CPS for decision making.

The overarching goal of the proposed research is to derive critical information and characterization of large scale generic nonlinear dynamical systems using limited observables. In the present state-of-the-art in data-driven dynamical system analysis, all the underlying state measurements and the time evolution of these states are required. Access to all of the dynamical states measurements in real-world is impossible or expensive. The objective of the proposal is to develop data-driven tools for dynamic system identification, classification and root-cause analysis of dynamic events, and prediction of system evolution. The research team will specifically conduct research on using available measurements to perform near real-time applications for various dynamic events that occur in electric power systems. The data analytics proposed are applicable to general non-linear dynamic systems and can be easily applied to other cyberphysical systems (CPS). More broadly, there is a large effort in the CPS and control community to model real world systems that we all interact with on a daily basis (such as transportation systems, communication networks, world wide web, etc.) as dynamical systems and thus, the theory and techniques developed through this project will enable online monitoring of these critical systems, allowing operators to quickly analyze these systems for any unstable/anomalous behavior from minimal data streams. The project will promote various educational and outreach activities including developing new courses, short courses, activities in schools, and scholarships for women and underrepresented minority students.

Active user participation in large-scale infrastructure systems, while presenting unprecedented opportunities, also poses significant challenges for the operator. One such example is electric power distribution systems, where the massive integration of distributed energy resources (DERs) and flexible loads motivates new decision-making paradigms via demand response through user engagement. This project introduces a novel approach for intelligent decision making in power distribution systems to efficiently leverage flexible demand commitments in highly uncertain and stochastic environments. The project goals are to (1) develop analytics required to enable actionable demand-side flexibility from several small consumers by adequately representing their constraints regarding electricity usage and their interactions with the system and the energy provider; and (2) develop a prototype for demand-side coordination using an open-source testbed for distribution systems management and evaluate the proposed algorithms with real-world utility data. Successful completion of this project will provide solutions to adaptive and smart infrastructure systems in which passive users turn into active participants. For the demand response focus here, this project will enable high levels of penetration of flexible loads and DERs economically through the transformation of grid operation from load following to supply following. The results from this project will provide valuable guidance to policymakers and electric utilities in managing aggregator-driven markets.

The availability of vast amounts of operational and end-user data in cyber-physical systems implies that paradigm improvements in monitoring and control can be attained via learning by many artificial intelligence agents despite them possessing vastly different abilities. Engaging this heterogeneous agent base in the context of the smart grid requires the use of hierarchical markets, wherein end-users participate in downstream markets collectively through aggregators, who in turn are coordinated by an upstream market. The goal of this project is to conduct a systematic study of such market-mediated learning and control. This project aims at much deeper levels of participation from end-users contributing electricity generation such as rooftop solar, shedding load via demand response, and providing storage capabilities such as electric vehicle batteries, to transform into reliable distributed energy resources (DER) at the level of wholesale markets. A methodological theme is multi-agent reinforcement learning (MARL) by agents that control physical systems via actions at different levels of the hierarchy. Underlying the whole project are well-founded physical models of the transmission and distribution grids, which provide structure to the problem domain and concrete use cases. This project facilitates a deeper level of decarbonization in the electricity sector, and contributes to climate change solutions by engineering a flat, interactive grid architecture that allows significant DERs to provide electricity services to both local and regional grids. Engagement with a grid-level market operator enables the project to address a problem space of immediate relevance to the current electricity grid. The project also includes the development of educational materials on data-analytics and energy systems. Intrinsic to the program are efforts at outreach to involve high-school students via demonstrations and lectures based on the technology developed.

This Cyber-Physical Systems (CPS) project will make foundational methodological advances that enable safe and robust reinforcement learning (RL)-based control algorithmic solutions that are driven by problems in smart traffic signal control systems. Recent advances in computation, communication, storage, and sensing have led to a demand for data-driven learning-based decision-making and control in modern cyber-physical systems (CPSs), such as smart transportation systems. In such systems, decision-making agents need to operate safely and in a robust manner while working in complex environments with constraints that need to be respected. This project will develop foundational advances in robust RL solutions, and safe and constrained RL with provable guarantees by taking traffic signal control systems within smart transportation systems as our motivating CPS application and evaluation platform. This work will additionally focus on advancing curriculum development, recruitment of students from under-represented groups, involvement of undergraduate students in research, K-12 outreach, and also research community outreach via workshops, conference sessions, and seminars. The researchers will interface with companies and other stakeholders to communicate the results of the research as well as provide them with educational material on methodology.

The project's impact is the engineering of more reliable, safer, and better performing next generation Cyber-Physical Systems (CPS) arising in domains involving automotive vehicles, medical devices, avionics, power grids, and autonomous agents. As these systems operate in environments that cannot always be perfectly anticipated/modeled, it is crucial that robustness be a prime objective right from the design phase. The project's novelty is the development of scalable and rigorous formal algorithmic approaches for facilitating such robust CPS engineering. These approaches advance classical discrete algorithmic techniques for use in quantitative environments in which CPS operates. The research aspect of the project is complemented with the creation of graduate and undergraduate courses teaching core logical and algorithmic analyses skills to scientists and engineers about to enter the workforce.

This Cyber Physical Systems (CPS) project will develop a theoretical framework that facilitates safe cooperative driving in heterogeneous traffic of human-operated and autonomously-operated vehicles and demonstrate its feasibility through both simulation and physical experiments. This project will help improve the safety of a transportation system currently being transformed by vehicles with growing autonomous features. By introducing an add-on device, or copilot, into legacy human-driven vehicles, this project will offer a smart driving assistant that is aware of the driver's behaviors and can alert the driver when the vehicle is at risk. When engaged in cooperative driving, the copilot will provide advice that reduces the chance of collision with nearby vehicles. By facilitating cooperative driving for both emerging autonomous vehicles and legacy human-driven vehicles, this project will foster a positive attitude of the public toward autonomous driving, therefore accelerating the adoption of autonomous vehicles into the transportation system. The education and outreach activities will raise more awareness of autonomous driving, Artificial Intelligence (AI) and robotics to the younger generation, and stimulate prospective students to pursue degrees and careers in science and engineering.

Human-cyber-physical systems (h-CPS) are interactive engineered systems that collaborate or interact with one or more human beings to leverage the complementary strengths of both human and autonomy technologies. Medical devices, robot assistive systems, teleoperation, semi-autonomous systems, and other technology-assisted applications are all examples of h-CPS. Because human operations are deeply intertwined with cyber and physical processes in h-CPS, new technical challenges for h-CPS analysis and design emerge, particularly in modeling complex human behaviors, enabling effective human-machine interactions, and developing reliable and high-performance controllers. Furthermore, as envisioned in future h-CPS subject to a large amount of data of adequate quality and quantity available from rich sensing modalities, modeling, interaction, and control procedures are shifting from model-based to data-driven, and new challenges such as trustworthiness and learning efficiency of data-driven methods are expected to arise. This project targets the unique challenges of data-driven modeling and control of h-CPS by developing a holistic data-driven design framework, accounting for addressing today's major barriers to apply data-driven approaches for modeling, interaction, and control of h-CPS. Educational and outreach activities are well-integrated into the research and include CPS workforce training, interdisciplinary research and curriculum development, and K-12 STEM outreach activities. The designed activities are uniquely positioned to attract members of underrepresented groups with a focus to enhance the diversity of the federal, state, and local CPS workforce.

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

Cyber-Physical Systems (CPS) sustainably benefit from software upgrades throughout their life cycles. However, as CPS become machine-learning-intensive due to rapidly increasing interactions between CPS and machine learning technologies, two major distinguishing factors associated with machine learning techniques raise significant safety concerns about CPS upgrades which play a critical role in enabling lifetime safety assurance. First, upgrades of machine learning components, which inherently result in system changes, come at significant safety risk for safety-critical CPS due to the vulnerabilities of machine learning techniques. Second, the traditional safe-by-verification upgrade framework, in which upgrades and verification have to be two separate procedures, is no longer valid for machine learning processes that update instantaneously during system operations. This project targets these unique challenges by developing scalable verification and monitoring methods for upgrades as well as safe upgrade procedures to enable trustworthy upgrades and achieve lifetime safety assurance in machine-learning-intensive CPS.

Deep Neural Networks (DNN) enabled Cyber-Physical Systems (CPS) hold great promise for revolutionizing many industries, such as drones and self-driving cars. However, the current generation of DNN cannot provide analyzable behaviors and verifiable properties that are necessary for safety assurance. This critical flaw in purely data-driven DNN sometimes leads to catastrophic consequences, such as vehicle crashes linked to self-driving and driver-assistance technologies. On the other hand, physics-model-based engineering methods provide analyzable behaviors and verifiable properties, but do not match the performance of DNN systems. These considerations motivate the work in this project which aims at physics-model-based neural networks (NN) redesign, yielding HyPhy-DNN: a hybrid self-correcting physics-enhanced DNN framework. HyPhy-DNN will provide the performance of DNNs and the analyzability and verifiability of physical models, thus providing a foundation for verifiably safe self-driving cars, drones, and other CPS systems. Moreover, the HyPhy-DNN will fundamentally advance the integration of deep learning and robust control to enable safety- and time-critical CPS to safely operate with high performance in unforeseen and dynamic environments.