With the advent of ubiquitous connectivity, large-scale data collection, and the remarkable successes of data driven artificial intelligence (AI) in recent years, we have come to a turning point. The time is ripe to consider how advanced data-driven AI technology will impact networked dynamical systems involving both human and machine agents together with physical infrastructure. This symposium will bring together leading experts from academia, government and industry to help identify promising directions in research and education at this nexus. The symposium will comprise invited talks, panel discussions, and brainstorming sessions. Striking the right balance between data-driven innovations and systematic design will be an important part of the conversation.

The outcomes of the symposium will include a meeting report distilled out of the panel discussions and the brainstorming sessions. The report will help inform government and industry stewards / stakeholders about new directions and grand challenges in this important area that will directly impact the nation's competitiveness and security in the coming decades.

The symposium will help identify new research directions at the crossroads of key areas of critical interest to NSF and the nation's research enterprise. NSF's Engineering Directorate has multiple major research programs related to AI and AI-enabled systems. The panel discussions, talks, brainstorming sessions, and the final symposium report will inform NSF and other government stakeholders who sponsor and exploit research and development in these critical areas.

How do we effectively teach both empirical data-driven and ?hard-science? methodology at the same overall number of credit hours? This is one of the key issues that will be discussed at the Symposium, and one of the most important questions we face as we redesign engineering curricula to accommodate the data-driven AI revolution. Bringing together world-class experts to discuss and offer insights on this and other related issues is of tremendous value for the next generation of AI-savvy systems and control engineers. In addition, the organizers will invite select students to participate in the Symposium, paying particular attention to female and URM representation.

The understanding of designing structured surfaces for advanced functionality, such as friction reduction, antifouling, and hydrophobicity, has significantly progressed over the years; however, the critical technical barrier to the application of these structured surfaces is the scalability in manufacturing capability. The biggest challenge in surface patterning is the process scalability, which needs to reconcile the significant scale difference between the individual feature size down to the nano- or micro-level and the large surface-to-be-textured up to the meter level. The project will investigate one vision for future manufacturing -- distributed robotic manufacturing -- to achieve scalable patterning of micro-structured functional surfaces using a cohort of mini-robots. The project will not only push the knowledge boundaries in the scientific understanding of distributed physical intelligence, machine-material interactions, and swarm control, but may open up a new and interdisciplinary research field at the intersection of manufacturing, robotics, control, and cyberphysical systems. Additionally, the project includes outreach at the Museum of Science and Industry in Chicago, open-source software, and curricular innovations, including online classes and training modules. The research will build an educational and outreach platform to enable education and workforce development for STEM educators, next generation workforce, and technical engineers.

The research objectives are to explore and answer three fundamental scientific questions that will enable the vision for future manufacturing in distributed robotic manufacturing. (1) Distributed physical intelligence: a new design framework will be established to distribute the intelligence among mechanical structures, analog circuits, and digital logics, as well as to design unconventional communication channels through both active and passive manners. (2) Unconventional machine-material interaction: new theoretical underpinnings will be established to investigate the machine-material interaction and the possible removal, deformation, and addition of material in this new paradigm, where the tools are extremely flexible and with significantly constrained power. (3) Swarm control: new fundamental knowledge will be generated from novel task decomposition and distribution paradigms to synthesis techniques capable of minimizing control effort, communication, and computation. Instead of top-down control of every individual mini-robot, novel methods will be established through which local rule specifications lead to global distributed pattern completion.

This Future Manufacturing award is supported by the Division of Computer and Network Systems (CNS) of the Directorate for Computer and Information Science and Engineering (CISE), and by the Division of Civil, Mechanical and Manufacturing Innovation (CMMI) of the Directorate for Engineering (ENG).

Large-scale systems with societal relevance, such as power generation systems, are increasingly able to leverage new technologies to mitigate their environmental impact, e.g., by harvesting energy from renewable sources. This NSF CPS project aims to investigate methods and computational tools to design a new user-centric paradigm for energy apportionment and distribution and, more broadly, for trustworthy utility services. In this paradigm, distributed networked systems will assist the end users of electricity in scheduling and apportioning their consumption. Further, they will enable local and national utility managers to optimize the use of green energy sources while mitigating the effects of intermittence, promote fairness, equity, and affordability. This project pursues a tractable approach to address the challenges of modeling and designing these large-scale, mixed-autonomy, multi-agent CPSs. The intellectual merits include new scalable methods, algorithms, and tools for the design of distributed decision-making strategies and system architectures that can assist the end users in meeting their goals while guaranteeing compliance with the fairness, reliability, and physical constraints of the design. The broader impacts include enabling the automated design of distributed CPSs that coordinate their decision-making in many applications, from robotic swarms to smart manufacturing and smart cities. The research outcomes will also be used in K-12 and undergraduate STEM outreach efforts.

The proposed framework, termed Automated Synthesis for Trustworthy Autonomous Utility Services (ASTrA), addresses the design challenges via a three-pronged approach. It uses population games to model the effect of distributed decision-making infrastructures (DMI) on large populations of strategic agents. DMIs will be realized via dedicated networked hybrid hardware architectures and algorithms we seek to design. ASTrA further introduces a systematic, layered methodology to automate the design, verification, and validation of DMIs from expressive representations of the requirements. Finally, it offers a set of cutting-edge computational tools to facilitate our methodology by enabling efficient reasoning about the interaction between discrete models, e.g., used to describe complex missions or embedded software components, and continuous models used to describe physical processes. The evaluation plan involves experimentation on a real testbed designed for zero-net-energy applications.

The purpose of this project is to develop new methods to increase the efficiency of freight activity, thereby reducing air pollution and greenhouse gas emissions associated with the freight sector. There are widespread inefficiencies in the freight transport system, many due to lack of coordination across actors in the system: railroads and trucking firms, shipping companies, cargo owners, and port operators. There is a need for a centrally coordinated freight management system that will optimize the flow of freight across the rail and road transportation networks. These networks are very complicated: freight and passengers share the same infrastructure; there is temporal and spatial variation in demand; there are many decision-makers affecting the system. We use optimization and control theory and techniques combined with behavioral models to develop a centrally managed control system. The fundamental concept is efficient freight load balancing, meaning allocating freight demand across time and space to serve the entire set of demands as efficiently as possible. In order to accomplish optimal load balancing, we must address two questions: 1) What is the most efficient and sustainable spatio-temporal allocation of freight shipments across the road network, and 2) what incentives and pricing tools will motivate users to accept this allocation. The second question is necessary, because a system optimization requires changes in behavior for some users relative to each user optimizing independently.

Our research approach is co-Simulation, Control and Optimization with BEhavioral incentives (SCOBE). We use simulation models as part of a closed loop optimization system where the system dynamics and user behavior are monitored and updated. Once we allow for variation in user preferences, conventional approaches to solving the system optimization problem are inadequate. Rather, we must take user preferences directly into account in order to determine the best combination of shipment allocations and user incentives. This project makes the following contributions: First, it advances science by developing a method for system optimization with variation in user preferences. Second, the resulting method will be demonstrated through the participation of at least one trucking company to evaluate its value in a real-world context. Third, particulate emissions from heavy duty trucks are one of the largest sources of human health impacts in urbanized areas. Increasing freight efficiency will reduce particulate and other emissions, as well as reduce greenhouse gas emissions. Fourth, the research will be used to promote under-represented undergraduate students to pursue graduate studies, and promote under-represented high school students to pursue careers in the science, technology, engineering and math (STEM) fields.

This Cyber-Physical Systems (CPS) grant will advance structural health monitoring of concrete structures by relying on data acquired by a novel sensing technology with unprecedented scalability and spatial resolution. Modern society depends critically on sound and steadfast functioning of a variety of engineering structures and infrastructures, such as bridges, buildings, pipelines, geotechnical structures, aircrafts, wind turbines, and industrial facilities. Due to aging, massive urbanization, and climate change, there is a growing need for accurate and reliable assessment of the health condition, performance, and operation of these structures in order to ensure their continuous functioning and safe use. The researched technology enables pervasive and scalable sensing of concrete structures with high resolution by transforming concrete into a smart self-sensing material, thereby enabling reliable long-term structural health monitoring. This in turn contributes to the nation?s sustainability and resilience and to advancing the nation?s prosperity, welfare, and security. The project advances multiple core research areas in structural health monitoring including CPS system architectures using embedded devices, multi-parameter sensing and networking based on radio frequency sensors, and machine learning for accurate and reliable data analytics. The research outcomes are highly translational to various other CPS domains. The project also contributes to secondary education and outreach activities in multiple ways as well as to undergraduate and graduate education.

The aim of this project is to create a novel sensing system comprised of radio frequency sensors that are pervasively embedded in large volumes of concrete structures and that sense their localities using radio frequency properties. The objective is the assessment of key parameters that reflect the behavior of the monitored structure under operational conditions, such as deformation, temperature, and humidity, as well as detection and characterization of damages. The project has the following intellectual contributions: 1) Passive radio frequency-based sensing that operates over a wide range of frequencies; architectures of smart exciters and networked radio frequency sensors that communicate among themselves via backscatter modulation; solar-powered radio frequency exciter platform that powers the sensors. 2) Energy-based sensing and network optimization of the radio frequency sensor network in terms of its monitoring ability and network connectivity given the constraints on the available harvested power at the exciters. 3) Machine learning methods for function estimation based on the principle of ensemble modeling with Gaussian processes and applied to self-localization and to inference of three-dimensional distributions of material parameters within large volumes of concrete structures.

The vision for Advanced Air Mobility (AAM) or formerly Urban Air Mobility (UAM) is to enable an air transportation system that moves people and cargo between places previously underserved by the current aviation market (local, regional, intraregional, urban) using revolutionary new electric vertical take-off and landing (eVTOL) aircraft. AAM has received significant attention from federal agencies. Companies around the globe are competing to build and test eVTOL aircraft to ensure the AAM will become an integral part of people?s daily life. The AAM has enormous economic potential and societal impact, but its success will depend on its ability to scale the operations to the expected high demand with safety guarantee.

This project lays the foundation of safe and scalable learning-based planning and control for autonomous air mobility. Concretely, the project will (i) focus on algorithmic advances of scalable multi-agent aircraft autonomy for real-time separation assurance to increase the airspace capacity; (ii) develop and integrate the online safety guard and offline adaptive stress testing model to provide safety enhancement for the multi-agent aircraft autonomy; (iii) design the collaborative traffic flow planning framework for flight operators and the airspace service provider to improve safety and efficiency when facing demand and capacity uncertainties on the AAM network; and (iv) integrate the developed models and algorithms to build an autonomous AAM ecosystem testbed to perform simulation/flight tests and system level validation. The multidisciplinary approach is based on multi-agent reinforcement learning, safe reinforcement learning, multi-agent stochastic game, and bi-level robust optimization. The proposed effort has transformative impacts to enable safe and scalable advanced air mobility. It could have impact in the way that other CPS tools are designed and implemented to support increasing autonomy and unmanned operations in civil aviation, autonomous cars/trucks, and robotics. The project has an integrated education plan in (i) student innovation competitions, teams and clubs; (ii) interdisciplinary curriculum development and improvement for AI and autonomy in aerospace; (iii) bringing industry experts to students in classroom; and (iv) international student research exchange. The project will engage elected officials and policy makers in AI and machine learning via podcast series, which will provide basic knowledge and insights on legal, ethical, and societal implications of AI. The project will establish a workforce pipeline from high school to postdoc for women in in aerospace via AI and computing.

This Cyber-Physical Systems (CPS) project aims at designing theories and algorithms for scalable multi-agent planning and control to support safety-critical autonomous eVTOL aircraft in high-throughput, uncertain and dynamic environments. Urban Air Mobility (UAM) is an emerging air transportation mode in which electrical vertical take-off and landing (eVTOL) aircraft will safely and efficiently transport passengers and cargo within urban areas. Guidance from the White House, the National Academy of Engineering, and the US Congress has encouraged fundamental research in UAM to maintain the US global leadership in this field. The success of UAM will depend on the safe and robust multi-agent autonomy to scale up the operations to high-throughput urban air traffic. Learning-based techniques such as deep reinforcement learning and multi-agent reinforcement learning are developed to support planning and control for these eVTOL vehicles. However, there is a major challenge to provide theoretical safety and robustness guarantees for these learning-based neural network in-the-loop models in multi-agent autonomous UAM applications. In this project, the researchers will collaborate with committed government and industry partners on the use-case-inspired fundamental research, with a focus on promoting safety and reliability of AI, machine learning and autonomy in students with diverse backgrounds.

The technical objectives of this project include (1) Safety and Robustness of Single-Agent Reinforcement Learning: in order to address the ?safety critical? UAM challenge, the PIs plan the min-max optimization for single agent reinforcement learning to formally build sufficient safety margin, constrained reinforcement learning to formulate safety as physical constraints in state and action spaces, and the novel cautious reinforcement learning that uses variational policy gradient to plan the safest aircraft trajectory with minimum distributional risk; (2) Safety and Robustness of Multi-Agent Reinforcement Learning: in order to address the ?heterogeneous agents and scalability? challenge, a novel federated reinforcement learning framework where a central agent coordinates with decentralized safe agents to improve traffic throughput while guaranteeing safety, and a scaling mechanism to accommodate a varying number of decentralized aircraft; (3) Safety and Robustness from Simulations to the Real World: in order to address the ?high-dimensionality and environment uncertainty? challenge, the researchers will focus on the agents? policy robustness under distribution shift and fast adaptation from simulation to the real world. Specifically, value-targeted model learning to incorporate domain knowledge such as the aircraft and environment physics, and a safe adaptation mechanism after the RL model is deployed online for flight testing or execution is planned.

Artificial Neural Networks (ANN) are increasingly being employed to monitor and control Cyber-Physical Systems (CPS), as in autonomous ground and aerial vehicles. With increasing complexity and safety criticality of these systems, formal-verification techniques that provide rigorous guarantees are urgently needed. The broad goal of the research is to develop novel algorithms and software tools for formal verification of ANN-controlled CPS (ANN-CPS). One of the main challenges of existing techniques is their scalability to large number of neurons and complex physical dynamics.

Using the novel concept of Interval Neural Networks, coupled with ideas from formal methods such as counter-example guided abstraction refinement and approximate bisimulation, the project investigates scalable formal verification techniques for ANN-CPS. The results of the project will enable rigorous analysis of complex ANN-CPS possible, thereby enhancing their reliability in applications such as autonomous driving. Further, the PI is engaged in course development, mentorship of undergraduate and graduate students, and outreach activities for K-12 students, with the broader aim of motivating and building the workforce for formal analysis of cyber-physical systems.

Light Detection and Ranging (LiDARs) and cameras are an indispensable part of the sensor suite used in autonomous cyber-physical systems such as self-driving cars and unmanned aerial vehicles. The data generated by these sensors is often processed by a deep neural network that transforms it into state estimates used in control loops. Although one can analyze the impact that erroneous state estimates have on control loops, less is known about how to characterize the errors produced by deep neural networks. The objective of this project is to develop analysis and design techniques that provide formally guaranteed bounds on how large these errors can be. Formally establishing error bounds will enable the verification of existing systems as well as the design of new autonomous systems for which formal guarantees of safety and performance can be given.

This project addresses the challenge of using deep neural networks in the perception pipeline of autonomous cyber-physical systems by following two different approaches, termed correctness-by-training and correctness-by-supervision. The first approach, correctness-by-training, is based on the use of monotone neural networks for which deterministic generalization bounds can be established. The challenge of using monotone neural networks is that their training is more challenging and several novel training techniques will be investigated. The second approach, correctness-by-supervision, consists of attaching a supervisor to the neural network that overrides the network output so as to enforce guaranteed error bounds. A supervisor will be developed in the context of localization using LiDAR measurements using novel point-set registration techniques based on moments. Both approaches aim to provide guaranteed error bounds on the state estimates computed by deep neural networks. The ultimate contribution is to use these error bounds in the formal analysis of safety and performance of control loops using deep neural networks in the perception pipeline.

The goal of this project is to improve how perception uncertainty is modeled in Cyber-Physical Systems (CPS). Complex autonomous CPS, from airplanes and unmanned aerial vehicles to future self-driving cars, permeate our daily lives. These systems consist of many interdependent components operating in highly uncertain environments and exhibiting complex dynamics. This interdependency makes not only their modeling harder but also quantifying their robustness more difficult. A single undetected faulty reading in sensors, delay in processing or error in communication protocols can lead to catastrophic events such as airplane or car accidents. Such events can lead to loss of life as well as fear or loss of confidence in the public. The approach of this project is to consider uncertainty as a function of time, rather than static estimates, which will enable researchers to quantify the robustness of the overall system. The broader impacts of the project include organization of a drone competition to be held at the University of Southern California (USC).

The modeling of uncertainty and reasoning about the robustness of highly complex CPS designs is crucial. While post-hoc analysis calls for improving sensing technology or fault tolerance through redundant sensors (or sensor fusion), in this project, we construct mathematical and algorithmic foundations to address research challenges in (1) mathematical models of time-varying uncertainty; (2) modeling of interdependent CPSs for analysis of interdependence as well as environment uncertainty; (3) quantification of robustness against such uncertainty; and (4) design of control strategies for these systems. Our approach is to develop a temporal logic-based framework for these complex interconnected CPS models. Augmenting formal specification techniques based on temporal logic with notions from statistics and information theory enables our framework to engineer high-confidence CPS applications that are adaptable and resilient.