Cyber-Physical Systems Virtual Organization | Fostering collaboration among CPS professionals in academia, government, and industry

CPS: Small: Collaborative Research: Tumor and Organs at Risk Motion: An Opportunity for Better DMLC IMRT Delivery Systems

Lead PI:

Ovidiu Daescu

Abstract

The objective of this research is to develop algorithms and software for treatment planning in intensity modulated radiation therapy under assumption of tumor and healthy organs motion. The current approach to addressing tumor motion in radiation therapy is to treat it as a problem and not as a therapeutic opportunity. However, it is possible that during tumor and healthy organs motion the tumor is better exposed for treatment, allowing for the prescribed dose treatment of the tumor (target) while reducing the exposure of healthy organs to radiation. The approach is to treat tumor and healthy organs motion as an opportunity to improve the treatment outcome, rather than as an obstacle that needs to be overcome. Intellectual Merit: The leading intellectual merit of this proposal is to develop treatment planning and delivery algorithms for motion-optimized intensity modulated radiation therapy that exploit differential organ motion to provide a dose distribution that surpasses the static case. This work will show that the proposed motion-optimized IMRT treatment planning paradigm provides superior dose distributions when compared to current state-of-the art motion management protocols. Broader Impact: Successful completion of the project will mark a major step for clinical applications of intensity modulated radiation therapy and will help to improve the quality of life of many cancer patients. The results could be integrated within existing devices and could be used for training of students and practitioners. The visualization software for dose accumulation could be used to train medical students in radiation therapy treatment planning.

Ovidiu Daescu

Performance Period: 09/15/2010 - 08/31/2014

Institution: University of Texas at Dallas

Sponsor: National Science Foundation

Award Number: 1035460

CPS: Small: Collaborative Research: Dynamical-Network Evaluation and Design Tools for Strategic-to-Tactical Air Traffic Flow Management

Lead PI:

Yan Wan

Abstract

The objective of the research is to develop tools for comprehensive design and optimization of air traffic flow management capabilities at multiple spatial and temporal resolutions: a national airspace-wide scale and one-day time horizon (strategic time-frame); and at a regional scale (of one or a few Centers) and a two-hour time horizon (tactical time-frame). The approach is to develop a suite of tools for designing complex multi-scale dynamical networks, and in turn to use these tools to comprehensively address the strategic-to-tactical traffic flow management problem. The two directions in tool development include 1) the meshed modeling/design of flow- and queueing-networks under network topology variation for cyber- and physical- resource allocation, and 2) large-scale network simulation and numerical analysis. This research will yield aggregate modeling, management design, and validation tools for multi-scale dynamical infrastructure networks, and comprehensive solutions for national-wide strategic-to-tactical traffic flow management using these tools. The broader impact of the research lies in the significant improvement in cost and equity that may be achieved by the National Airspace System customers, and in the introduction of systematic tools for infrastructure-network design that will have impact not only in transportation but in fields such as electric power network control and health-infrastructure design. The development of an Infrastructure Network Ideas Cluster will enhance inter-disciplinary collaboration on the project topics and discussion of their potential societal impact. Activities of the cluster include cross-university undergraduate research training, seminars on technological and societal-impact aspects of the project, and new course development.

Yan Wan

Performance Period: 09/01/2010 - 08/31/2014

Institution: University of North Texas

Sponsor: National Science Foundation

Award Number: 1035386

CPS: Small: Collaborative Research: Dynamical-Network Evaluation and Design Tools for Strategic-to-Tactical Air Traffic Flow Management

Lead PI:

Sandip Roy

Abstract

Sandip Roy

Performance Period: 09/01/2010 - 08/31/2014

Institution: Washington State University

Sponsor: National Science Foundation

Award Number: 1035369

CPS: Small: Sensor Lattices

Lead PI:

Steven Lavalle

Abstract

Using the newly introduced idea of a sensor lattice, this project conducts a systematic study of the "granularity'' at which the world can be sensed and how that affects the ability to accomplish common tasks with cyber-physical systems (CPSs). A sensor is viewed as a device that partitions the physical world states into measurement-invariant equivalence classes, and the sensor lattice indicates how all sensors are related. Several distinctive characteristics of the pursued approach are: 1) Virtual sensor models are developed, which correspond to minimal information requirements of common tasks and are independent of particular physical sensor implementations. 2) Uncertainty is decoupled into disturbances and pre-images, the latter of which yields the measurement-invariant equivalence classes and sensor lattice. 3) The development of particular spatial and temporal filters that are based on minimal information requirements of a task. 4) Formally establishing the conditions that enable sensors in a CPS to be interchanged, and then determining the relative complexity tradeoffs. The intellectual merit is to understand how mappings from the physical world to sensor outputs affect the solvability and complexity of commonly occurring tasks. This is a critical step in the development of mathematical and computational CPS foundations. Broader impact is expected by improving design methodologies for CPS solutions to societal problems such as assisted living, environmental monitoring, and automated agriculture. The sensor lattice approach is transformative because it represents a new paradigm with which to address basic sensor-based inference issues, which extend well beyond the traditional academic boundaries.

Steven Lavalle

Performance Period: 09/01/2010 - 09/30/2016

Institution: University of Illinois at Urbana-Champaign

Sponsor: National Science Foundation

Award Number: 1035345

CPS: Medium: Collaborative Research: Architecture and Distributed Management for Reliable Mega-scale Smart Grids

Lead PI:

Panganamala Kumar

Co-Pi:

Shobha Vasudevan

Abstract

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.

Panganamala Kumar

Performance Period: 09/15/2010 - 08/31/2012

Institution: University of Illinois at Urbana-Champaign

Sponsor: National Science Foundation

Award Number: 1035340

CPS: Medium: Collaborative Research: Body Area Sensor Networks: A Holistic Approach from Silicon to Users

Lead PI:

David Wentzloff

Abstract

Body Area Sensor Networks: A Holistic Approach from Silicon to Users The objective of this research is to develop new principles and techniques for adaptive operation in highly dynamic physical environments, using miniaturized, energy-constrained devices. The approach is to use holistic cross-layer solutions that simultaneously address all aspects of the system, from low-level hardware design to higher-level communication and data fusion algorithms to top-level applications. In particular, this work focuses on body area sensor networks as emerging cyber-physical systems. The intellectual merit includes producing new principles regarding how cyber systems must be designed in order to continually adapt and respond to rapidly changing physical environments, sensed data, and application contexts in an energy-efficient manner. New cross-layer technologies will be created that use a holistic bottom-up and top-down design -- from silicon to user and back again. A novel system-on-a-chip hardware platform will be designed and fabricated using three cutting-edge technologies to reduce the cost of communication and computation by several orders of magnitude. The broad impact of this project will enable the wide range of applications and societal benefits promised by body area networks, including improving the quality and reducing the costs of healthcare. The technology will have broad implications for any cyber physical system that uses energy constrained wireless devices. A new seminar series will bring together experts from many fields (including domain experts, such as physicians and healthcare professionals). The key aspects of this work that deal with healthcare have the potential to attract women and minorities to the computer field.

David Wentzloff

Performance Period: 10/01/2010 - 09/30/2013

Institution: University of Michigan Ann Arbor

Sponsor: National Science Foundation

Award Number: 1035303

CPS: Small: Fundamental Limitations for Classes of Cooperative Multi-Agent Systems

Lead PI:

James Freudenberg

Abstract

The objective of this research is to study such properties of classes of cooperative multi-agent systems as stability, performance, and robustness. Multi-agent systems such as vehicle platoons and coupled oscillators can display emergent behavior that is difficult to predict from the behavior of individual subsystems. The approach is to develop and extend the theory of fundamental design limitations to cover multi-agent systems that communicate over both physical and virtual communication links. The theory will further describe known phenomena, such as string instability, and extend the analysis to other systems, such as harmonic oscillators. The theory will be tested and validated in the Michigan Embedded Control Systems Laboratory. The intellectual merit of the proposed research will be the development of tools that delineate tradeoffs between performance and feedback properties for control systems involving mixes of human and computer agents and classes of hardware dynamics, controllers, and network topology. The contribution to system behavior of each agent's realization in hardware (constrained by Newton's laws) and realization in software and communications (subject to the constraints discovered by Shannon and Bode) will be assessed. The broader impacts of the proposed research will be a significant impact on teaching, both at the University of Michigan and at ETH Zurich. At each school, popular teaching laboratories allow over 100 students per year, from diverse backgrounds, to learn concepts from the field of embedded networked distributed control systems. New families of haptic devices will enable the research to be transferred into these teaching laboratories.

James Freudenberg

Performance Period: 09/15/2010 - 08/31/2015

Institution: University of Michigan Ann Arbor

Sponsor: National Science Foundation

Award Number: 1035271

Robust Capacity-Constrained Scheduling and Data-Based Model Refinement for Enhanced Collision Avoidance in Low-Earth Orbit

Lead PI:

Jeffrey Anderson

Abstract

The objective of this research is to improve the ability to track the orbits of space debris and thereby reduce the frequency of collisions. The approach is based on two scientific advances: 1) optimizing the scheduling of data transmission from a future constellation of orbiting Cubesats to ground stations located worldwide, and 2) using satellite data to improve models of the ionosphere and thermosphere, which in turn are used to improve estimates of atmospheric density. Intellectual Merit Robust capacity-constrained scheduling depends on fundamental research on optimization algorithms for nonlinear problems involving both discrete and continuous variables. This objective depends on advances in optimization theory and computational techniques. Model refinement depends on adaptive control algorithms, and can lead to fundamental advances for automatic control systems. These contributions provide new ideas and techniques that are broadly applicable to diverse areas of science and engineering. Broader Impacts Improving the ability to predict the trajectories of space debris can render the space environment safer in both the near term---by enhancing astronaut safety and satellite reliability---and the long term---by suppressing cascading collisions that could have a devastating impact on the usage of space. This project will impact real-world practice by developing techniques that are applicable to large-scale modeling and data collection, from weather prediction to Homeland Security. The research results will impact education through graduate and undergraduate research as well as through interdisciplinary modules developed for courses in space science, satellite engineering, optimization, and data-based modeling taught across multiple disciplines.

Jeffrey Anderson

Performance Period: 09/15/2010 - 08/31/2014

Institution: University Corporation For Atmospheric Research

Sponsor: National Science Foundation

Award Number: 1035250

CPS: Medium: Collaborative Research: Robust Capacity-Constrained Scheduling and Data-Based Model Refinement for Enhanced Collision Avoidance in Low-Earth Orbit

Co-Pi:

Abstract

Dennis Bernstein

Professor Bernstein's interest include identification, estimation, and control for aerospace applications. His research has focused on active noise and vibration control, as well as attitude control for space applications. His current interests are in the theory and application of nonlinear system identification, large-scale state estimation for data assimilation, and adaptive control. He is directorof the Noise, Vibration, and Motion Control Laboratory, which includes instrumentation and testbeds for control applications. A 6-degree-of-freedom electric shaker table under all-digital control is used for vibration and motion control applications. Facilities are available for implementing and testing algorithms for active noise and vibration control. Current research is focusing on adaptive command following and disturbance rejection algorithms for systems with uncertain dynamics and unknown disturbance spectra. He is co-director (with Ilya Kolmanovsky) of the Attitude Dynamics and Control Laboratory. In this laboratory, a triaxial air bearing is used to develop and implement adaptive control algorithms for spacecraft applications. He was Editor-in-Chief of the IEEE Control Systems Magazine from 2003 to 2011. Prof. Bernstein has authored more than 200 journal papers and 350 conference papers. He is the author of Matrix Mathematics, which is published by Princeton University Press. (A review of Matrix Mathematics can be downloaded from:<a class="link" href="http://www.siam.org/news/news.php?id=125" style="margin: 0px; padding: 0px; outline: none; text-decoration: none; color: rgb(0, 51, 102) !important; border-bottom-width: 1px !important; border-bottom-style: dotted !important; border-bottom-color: rgb(153, 204, 255) !important; " target="_blank">http://www.siam.org/news/news.php?id=125</a>) Matrix Mathematics - Errata and Addenda

Performance Period: 09/15/2010 - 08/31/2014

Institution: University of Michigan Ann Arbor

Sponsor: National Science Foundation

Award Number: 1035236

CPS: Small: The Roles of Communications in Lane Merging Systems

Lead PI:

Nicholas Maxemchuk

Abstract

Vehicle automation has progressed from systems that monitor the operation of a vehicle, such as antilock brakes and cruise control, to systems that sense adjacent vehicles, such as emergency braking and intelligent cruise control. The next generation of systems will share sensor readings and collaborate to control braking operations by looking several cars ahead or by creating safe gaps for merging vehicles. Before we allow collaborative systems on public highways we must prove that they will do no harm, even when multiple rare events occur. The events will include loss of communications, failures or inaccuracies of sensors, mechanical failures in the automobile, aggressive drivers who are not participating in the system, and unusual obstacles or events on the roadways. The rules that control the interaction between vehicles is a protocol. There is a large body of work to verify the correctness of communications protocols and test that different implementations of the protocol will interact properly. However, it is difficult to apply these techniques to the protocols for collaborative driving systems because they are much more complex: 1) They interact with the physical world in more ways, through a network of sensors and the physical operation of the automobile as well as the communications channel; 2) They perform time critical operations that use multiple timers; And, 3) they may have more parties participating. In [1] we have verified that a three party protocol that assists a driver who wants to merge between two cars in an adjacent lane will not cause an accident for combinations of rare events. The verification uses a probabilistic sequence testing technique [2] that was developed for communications protocols. We were only able to use the communications technique after designing and specifying the collaborative driving protocol in a particular way. We have generalized the techniques used in the earlier work so that we can design collaborative driving protocols that can be verified. We have 1) a non-layered architecture, 2) a new class of protocols based upon time synchronized participants, and 3) a data management rule. 1) Communications protocols use a layered architecture. Protocol complexity is reduced by using the services provided by a lower layer. The layered architecture is not sufficient for collaborative driving protocols because they operate over multiple physical platforms. Instead, we define a smoke stack architecture that is interconnected. 2) The operation of protocols with multiple timers is more difficult to analyze because there are different sequences of operations depending on the relative times when the timers are initiated. Instead of using timers, we design protocols that use absolute time. This is reasonable because of the accurate time acquired from GPS and the accuracy of current clocks while GPS is not available. 3) Finally, in order for programs in different vehicles to make the same decisions they must use the same data. Our design merges the readings of sensors in different vehicles and uses a communications protocol that guarantees that all vehicles have the same sequence of messages and only use the messages that all vehicles have acquired. 1. Bohyun Kim, N. F. Maxemchuk, "A Safe Driver Assisted Merge Protocol," IEEE Systems Conference 2012, 19-22 Mar. 2012, Vancouver, BC, Canada, pp. 1-4. 2. N. F. Maxemchuk, K. K. Sabnani, "Probabilistic Verification of Communication Protocols," Distributed Computing Journal, Springer Verlag, no. 3, Sept. 1989, pp. 118-129.

Nicholas Maxemchuk

Performance Period: 09/01/2010 - 08/31/2014

Institution: Columbia University

Sponsor: National Science Foundation

Award Number: 1035178

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