1. Verification and control of continuous and hybrid systems
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In control problems, "complex" models, such as systems of
differential equations, are usually checked against "simple"
specifications, such as stability, set invariance, controllability
and observability. In formal analysis (verification), "rich"
specifications such as languages and formulas of temporal logics,
are checked against "simple" models of software programs and
digital circuits, such as (finite) transition graphs. The most
widespread specifications include safety, i.e., something bad
never happens and liveness, i.e., something good eventually
happens. We are developing computational tools for bridging in
this gap, and therefore allowing for specifying the properties of
continuous and hybrid systems in a rich language, with automatic
verification and controller synthesis.
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2. Formal approaches to planning and control of robot motion
Robot motion tasks are usually specified simply as "Go form A to B
and avoid collisions". By using tools from formal methods,
concurrency, and control theory, we extend motion specification
languages to arbitrary temporal and logic statements given in
natural language, and develop tools for provably correct automatic
deployment of robots and teams of robots from such specifications.
2.1 Hierarchical abstractions for planning and control of robotic swarms
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Specifying, planning, and controlling the motion of very large
teams of small and inexpensive mobile robots, or swarms, is a
challenging problem. We use tools from differential geometry and
formal analysis to construct a hierarchical abstraction framework
for robotic swarms. In this framework, high level swarm
specifications given in terms of temporal and logic statements
about a small set of essential features of the swarm are
automatically converted into provably correct robot control and
local communication strategies.
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2.2 Automatic deployment of autonomous cars in a miniature Robotic
Urban-Like Environment (RULE).
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RULE is an experimental platform for automatic deployment of
robotic cars in an urban-like environment. The cars are Khepera
III miniature robots with processing, sensing, and communication
capabilities. The "city" has streets, intersections, traffic
lights, and parking spots, and can be easily reconfigured. The
goal is to be able to simultaneously deploy multiple cars from
human-like, rich specifications about visiting regions of interest
in the city such as "Visit Road 1 and then Road 2, in this order,
infinitely often. If Intersection 1 is ever reached, then Road 4
should never be entered. Park in the next available parking slot",
etc.
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3. Modeling, analysis, and control of bacterial metabolic and gene networks
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Bacteria continuously respond to environmental changes through a
complicated mechanism consisting of an interplay between metabolic
and genetic networks. Through hundreds of chemical reactions, the
metabolic network converts nutrients from the environment to
elements necessary for growth and survival of the cell. Most of
these chemical reactions are regulated by enzymes produced by a
genetic network. In turn, the expression of the genes from the
genetic network is regulated by its own products and metabolites
produced by the metabolic network.
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3.1 Genome scale metabolic analysis
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We use tools from convex analysis to study the robustness of
metabolism to mutations and environmental changes, to understand
evolutionary constraints, and to design gene perturbations and
environmental conditions leading to specific desired phenotypes.
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3.2 Modeling, analysis, synthesis, and control of gene networks
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By using techniques from formal analysis and control theory, we
develop tools for analysis, synthesis, and control of gene
networks. We are particularly interested in synthetic gene
networks.
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