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.

The objective of this research is to check correct functioning of cyber-physical systems during their operation. The approach is to continuously monitor the system and raise an alarm when the system seems to exhibit an erroneous behavior. Correct functioning of cyber-physical systems is of critical importance. This is more so in safety critical systems like medical, automotive and other applications. The approach employs hybrid automata for specifying the property to be monitored and for modeling the system behavior. The system behavior is probabilistic in nature due to noise and other factors. Monitoring such systems is challenging since the monitor can only observe system outputs, but not it's state. Fundamental research, on defining and detecting whether a system is monitorable, is the focus of the work. The project proposes accuracy measures and cost based metrics for optimal monitoring. The project is developing efficient and effective monitoring techniques, based on product automata and Partially Observable Markov Decision Processes. The results of the project are expected to be transformative in ensuring correct operation of systems. The results will have impact in many areas of societal importance and utility for daily life, such as health care, nursing/rehabilitation, automotive systems, home appliances, and more. The benefits in nursing/rehabilitation emanate from the deployment of advanced technologies to assist caregivers. This can lead to improved health and quality of life of older patients at reduced costs. The project includes education and outreach in the form of K-12 outreach and involvement of undergraduate and graduate students in research. The project is committed to involving women and minorities in education and research.

The objective of this research is to develop methods and tools for a multimodal and multi-sensor assessment and rehabilitation game system called CPLAY for children with Cerebral Palsy (CP). CPLAY collects and processes multiple types of stimulation and performance data while a child is playing. Its core has a touch-screen programmable game that has various metrics to measure delay of response, score, stamina/duration, accuracy of motor/hand motion. Optional devices attached to extend CPLAY versions provide additional parallel measurements of level of concentration/participation/engagement that quantify rehabilitation activity. The approach is to model the process as a cyber-physical system (CPS) feedback loop whereby data collected from various physical 3D devices (including fNIR brain imaging) are processed into hierarchical events of low-to-high semantic meaning that impact/ adjust treatment decisions. Intellectual Merit: The project will produce groundbreaking algorithms for event identification with a multi-level data to knowledge feedback loop approach. New machine learning, computer vision, data mining, multimodal data fusion, device integration and event-driven algorithms will lead towards a new type of cyber- physical rehabilitation science for neurological disorders. It will deliver fundamental advancements to engineering by showing how to integrate physical devices with a computationally quantitative platform for motor and cognitive skills assessment. Broader Impacts: The project delivers a modular & expandable game system that has huge implications on the future of US healthcare and rehabilitation of chronic neurological disabilities. It brings hope to children with Cerebral Palsy via lower cost and remote rehabilitation alternatives. It brings new directions to human centered computing for intelligent decision-making that supplements evidence-based practices and addresses social and psychological isolation problems.

The objective of this research is to establish a foundational framework for smart grids that enables significant penetration of renewable DERs and facilitates flexible deployments of plug-and-play applications, similar to the way users connect to the Internet. The approach is to view the overall grid management as an adaptive optimizer to iteratively solve a system-wide optimization problem, where networked sensing, control and verification carry out distributed computation tasks to achieve reliability at all levels, particularly component-level, system-level, and application level. Intellectual merit. Under the common theme of reliability guarantees, distributed monitoring and inference algorithms will be developed to perform fault diagnosis and operate resiliently against all hazards. To attain high reliability, a trustworthy middleware will be used to shield the grid system design from the complexities of the underlying software world while providing services to grid applications through message passing and transactions. Further, selective load/generation control using Automatic Generation Control, based on multi-scale state estimation for energy supply and demand, will be carried out to guarantee that the load and generation in the system remain balanced. Broader impact. The envisioned architecture of the smart grid is an outstanding example of the CPS technology. Built on this critical application study, this collaborative effort will pursue a CPS architecture that enables embedding intelligent computation, communication and control mechanisms into physical systems with active and reconfigurable components. Close collaborations between this team and major EMS and SCADA vendors will pave the path for technology transfer via proof-of-concept demonstrations.

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 to develop formal verification tools for human-computer interfaces to cyber-physical systems. The approach is incorporating realistic assumptions about the behavior of humans into the verification process through mathematically constructed "mistake models" for common types of mistakes committed by the operator during an interactive task. Exhaustive verification techniques are used to expose combinations of human mistakes that can lead to system-wide failures. The techniques are evaluated using case studies involving medical device interfaces. The problem of verifying human-machine interfaces requires new approaches that combine rigorous formal verification techniques with the empirical human-centered approach to user-interface evaluation. The research addresses challenges of integrating empirical user-study data into formal game-based models that describe common types of operator mistakes. Using these models to detect subtle flaws in user-interface design is also a challenge. It is well-known that a poorly designed interface will enable harmful operator errors, which remain a major cause of failures in a wide variety of safety-critical cyber-physical systems. This project will automate user-interface verification by detecting likely defects, early in the design process. Open source verification tools will be made freely available to the community at large. The ongoing research will be integrated into a set of graduate-level computer science courses focused on the theme of "Safety in Human Computer Interfaces". Results from the project will also be integrated into educational materials for the ongoing eCSite GK12 project with the goal of promoting awareness of user-interface design issues amongst high school students.

The objective of this research is to develop an atomic force microscope based cyber-physical system that can enable automated, robust and efficient assembly of nanoscale components such as nanoparticles, carbon nanotubes, nanowires and DNAs into nanodevices. The proposed approach is based on the premise that automated, robust and efficient nanoassembly can be achieved through tip based pushing in an atomic force microscope with intermittent local scanning of nanoscale components. In particular, in order to resolve temporally and spatially continuous movement of nanoscale components under tip pushing, we propose the combination of intermittent local scanning and interval non-uniform rational B-spline based isogeometric analysis in this research. Successful completion of this research would lead to foundational theories and algorithmic infrastructures for effective integration of physical operations (pushing and scanning) and computation (planning and simulation) for robust, efficient and automated nanoassembly. The resulting theories and algorithms will also be applicable to a broader set of cyber physical systems. If successful, this research will lead to leap progress in nanoscale assembly, from prototype demonstration to large-scale manufacturing. Through its integrated research, education and outreach activities, this project will provide advanced knowledge in cyber-physical systems and nanoassembly for students from high schools to graduate schools and will increase domestic students? interest in science and engineering and therefore strengthen our competitiveness in the global workforce.

The objective of this research is the creation of a coastal observing system that enables dense, in situ, 4D sensing through networked, sensor-equipped underwater drifters. The approach is to develop the technologies required to deploy a swarm of autonomous buoyancy controlled drifters, which are vehicles that can control their depth, but are otherwise carried entirely by the ocean currents. Such Lagrangian sampling promises to deliver a wealth of new data, ranging from applications in physical oceanography (mapping 3D currents), biology (observing the dispersion of larvae and nutrients), environmental science (tracking coastal pollutants and effluents from storm drains), and security (monitoring harbors and ports). This observing system fundamentally requires accurate positions of the drifters (to interpret the spatial correlations of data samples), swarm control algorithms (to achieve desired sampling topologies), and wireless communication (to coordinate between the individual drifters). This research will create distributed techniques to self-localize the drifter swarm, novel swarm control algorithms that enable topology manipulation while purely leveraging the stratified flow environment, and efficient wireless underwater communication for information sharing. This project has significant societal impact and educational elements. Underwater drifter swarms will enable novel insights into a wide array of scientific questions, including understanding plankton transport, accumulation and dispersion as well as monitoring harmful algal blooms. Undergraduates will play an active role in many aspects of this project, thereby offering them a uniquely interdisciplinary experience. Finally, outreach to high school students will occur through the UCSD COSMOS summer program.

The objective of this research is to develop new methods for verifying the safety of complex cyber-physical systems based on information derived from the wide variety of models and methods used throughout the design process. The approach is based on a new formalism to represent the architecture of systems with cyber components, physical components, and interconnections between these domains. Diverse engineering models of different aspects of the system will be associated through the cyber-physical architecture for the complete system. Formal logic will be developed to express and reason about inter-model consistency and to infer system-level properties from information derived from the domain-specific models. The project's intellectual merit lies in the creation of a comprehensive, unified framework for verifying properties of systems rich in both cyber and physical components. The new formal logic will make it possible to integrate information from the wide range of engineering domains and technical expertise required to design complex systems. This will lead to a principled, rigorous approach to system-level verification engineering for real-world cyber-physical systems. The application of the new methodology to verify the safety of cooperative intersection collision avoidance systems will have immediate impact on emerging technologies for safer automobile systems. A new interdisciplinary course in engineering and computer science on system-level design of cyber-physical systems will prepare a new cadre of graduates with the cross-cutting skills needed to develop safety-critical systems. Innovative educational modules will also be developed to inspire pre-college students to pursue education and careers in engineering and computer science.

The objective of this research is to develop advanced distributed monitoring and control systems for civil infrastructure. The approach uses a cyber-physical co-design of wireless sensor-actuator networks and structural monitoring and control algorithms. The unified cyber-physical system architecture and abstractions employ reusable middleware services to develop hierarchical structural monitoring and control systems. The intellectual merit of this multi-disciplinary research includes (1) a unified middleware architecture and abstractions for hierarchical sensing and control; (2) a reusable middleware service library for hierarchical structural monitoring and control; (3) customizable time synchronization and synchronized sensing routines; (4) a holistic energy management scheme that maps structural monitoring and control onto a distributed wireless sensor-actuator architecture; (5) dynamic sensor and actuator activation strategies to optimize for the requirements of monitoring, computing, and control; and (6) deployment and empirical validation of structural health monitoring and control systems on representative lab structures and in-service multi-span bridges. While the system constitutes a case study, it will enable the development of general principles that would be applicable to a broad range of engineering cyber-physical systems. This research will result in a reduction in the lifecycle costs and risks related to our civil infrastructure. The multi-disciplinary team will disseminate results throughout the international research community through open-source software and sensor board hardware. Education and outreach activities will be held in conjunction with the Asia-Pacific Summer School in Smart Structures Technology jointly hosted by the US, Japan, China, and Korea.