|
|
Networked
Cyber Physical Systems at SRI |
|
The increasing
availability of devices that can sense and affect their environment in
different ways and with different levels of sophistication is the starting
point for development of a new generation of Networked Cyber-Physical Systems
(NCPS). Such systems provide complex, situation-aware, and often critical
services. Examples include traffic control, medical systems, home automation,
flexible manufacturing systems, automated laboratories, micro-climate control
in buildings, structural monitoring and control, self-assembling structures
or systems, unmanned vehicles, networked satellite missions, deep space
exploration, and instrumented spaces for surveillance, emergency response, or
social networking. A Logical Framework for
Self-Optimizing Networked Cyber-Physical Systems Networked Cyber-Physical Systems (NCPS) present many
challenges that are not suitably addressed by existing distributed computing
paradigms. They must be reactive and maintain an overall situation awareness
that emerges from partial distributed knowledge. They must achieve system
goals through local, asynchronous actions, using (distributed) control loops
through which the environment provides essential feedback. Typical NCPS are
open, dynamic, and heterogeneous in many dimensions, and often need to be
rapidly instantiated and deployed for a given mission. Although work on
cyber-physical systems is often concerned with the engineering challenge of
integrating software with the physical world, it is becoming increasingly
clear that more fundamental work is needed to address real-world challenges
in a uniform and systematic way. Our work is motivated by the observation that especially
in challenging environments, that exhibit many forms of unreliability and
failures, the physical world imposes severe limitations on how distributed
algorithms can operate. We believe that traditional models of distributed
computing are too abstract to provide an adequate foundation. Inspired by
earlier work on delay- and disruption-tolerant networking, we have developed
a distributed computing model based on partially ordered knowledge sharing
that makes very few assumptions about the underlying network, its topology,
and its characteristics. A distinguishing feature of our model is the use of
a partial order to exploit the abstract semantics of knowledge and allow it
to be replaced in a distributed fashion while it is cached in the network. A
prototype of the model has been implemented in what we call a
cyber-application framework that can support simulation and analysis of NCPS
applications as well as their deployment on, e.g. multi-processor/multi-core
architectures, computing clusters of various flavors, mobile ad hoc networks,
and combinations. On top of this loosely coupled distributed computing
model, we are currently pursuing a declarative approach to provide an
abstraction from the high complexity of NCPS and avoid error-prone and
time-consuming low-level programming. Our long-term goal is to develop
a distributed computational and logical foundation that supports a wide
spectrum of system operation between autonomy and cooperation to adapt to
resource constraints, in particular to limitations of computational, energy,
and networking resources. Related Projects at SRI: á
DTN: Delay- and
Disruption-Tolerant Networking á
Centibots: Coordinated deployment
of 100 robots for missions such as urban surveillance á
Commbots: Self-organizing
team of mobile robots to maximize network performance
á
KARTO: SDK for use in robotic
navigation, mapping and exploration á
xTune: A formal methodology for
cross-layer tuning of mobile real-time embedded systems á
Group communication:
A formal specification of the Spread group communication system Principles and Foundations
for Fractionated Networked Cyber-Physical Systems Related Project
at SRI: á
Pathway Logic: Analysis of biological
entities and processes based on rewriting logic |
|||||||||||||||||||||
|
|
Last updated: July
12, 2010