S4
System Synthesis and Supervision, Scenarios
Benoît Caillaud
20 March 2012
Objectives since last evaluation
Embedded system design: foundations & applications
Interfaces for reactive components
Methodology: Contract-based design
Modeling: Interface theories, modal specifications and their timed and
stochastic extensions
Composing: Compositional reasoning methods
Algorithms & tools: Modal interfaces, contract-based design
Supervisory control
Opacity: control of information flow in open systems
Petri-Net theory
Synthesis: synthesis of concurrent/distributed systems
Benoît Caillaud – S4
21 March 2012 - 2
People & competences
Eric Badouel
Albert Benveniste
Benoit Caillaud
Philippe
Darondeau
Axel Legay
Sophie Pinchinat
Models of concurrency & Petri nets, Supervisory Control, Timed systems
Probability & statistics, Hybrid modeling
Models of concurrency & Petri nets, Probability & statistics, Supervisory
Control, Hybrid modeling, Tool Development
Models of concurrency & Petri nets, Supervisory Control, Timed systems
Probability & statistics, Timed systems
Logics & Games, Supervisory Control, Timed systems
Benoît Caillaud – S4
21 March 2012 - 3
Topics and major results
Contract-based design and interface theories
• Modal interfaces as an algorithmic foundation of contract-based reasoning (residuation of modal
specifications)
• Quantitative interfaces: Timed modal specifications, Timed I/O automata, probabilistic contracts,
constraint Markov chains
• Mica: Modal interface compositional analysis Ocaml library
Supervisory control
• Opacity: optimal control of information flow in open systems
• Supervisory control of modal specifications of services
• Solution to the quasi-static scheduling problem
• Residuation of tropical power series
Hybrid modeling (Synchronics LSIA)
• Non-standard semantics of hybrid systems
• Synchronous dataflow hybrid modeling language
Petri-net theory
• PN-based synthesis of distributed controllers
• Decomposition theory for persistent PN
Benoît Caillaud – S4
21 March 2012 - 4
Modal Interfaces
Benoît Caillaud
21 March 2012
Modal Interfaces: algorithmic foundation
of (A,G) contracts
<
System A
Specification algebra supporting:
• Contract-based design
×
Cont
Cont
Cont ract
Cont
ract
B4
ractractB3
B1 B2
• Compositional reasoning
Cont
Cont
Cont ract
Cont
ract
B1
ractractB1
C1 B1
Subsystem B
Subsystem C
≤?
• Efficient algorithms
Cont
Cont
Cont ract
Cont
ract
B4
ract
ract B3
D1 B2
Component D
Benoît Caillaud – S4
<
<
×
<
• Multiple viewpoints
≤?
<
• Independent implementability
Cont
Cont
Cont ract
Cont
ract
B4
ract
ract B3
A1 B2
Cont
Cont
Cont ract
Cont
ract
B4
ractractB3
E1 B2
Component E
21 March 2012 - 6
Modal Interfaces
Deterministic I/O modal transition system: transitions are given
a label may or/and must
• may transitions are dashed
overload?
overload?
• must transitions are solid
a
nack!
sent?
A
f
b
ack!
sent?, overload?
• implementation: must everywhere
sent?
ack!
nack!
• refinement: simulation rel. strengthening must and weakening may
• extend Interface Automata, ~ conjunctive fragment μ-calculus,
• polynomial complexity (unlike μ-calculus)  prototype tool Mica
Benoît Caillaud – S4
21 March 2012 - 7
Modal Interfaces: algebraic properties
Benoît Caillaud – S4
21 March 2012 - 8
Opacity control
Benoît Caillaud
21 March 2012
Supervisory control for opacity in open systems
Benoît Caillaud – S4
21 March 2012 - 10
Concurrent Secrets
Benoît Caillaud – S4
21 March 2012 - 11
Hybrid Modeling
Benoît Caillaud
21 March 2012
The non-standard semantics of hybrid systems
Programming/modeling language perspective:
• discrete synchronous real-time programming: solid foundations
(constructive semantics,…) for languages and commercial tools (SCADE)
• hybrid modeling: commercial tools (Simulink, Dymola), however
foundations are not as solid
Better understand the combination of discrete and continuous
components: non-standard semantics of hybrid systems:
• constructive semantics based on non-standard real analysis
• synchronization between continuous and discrete parts: zero-crossings
• compilation of a SDF hybrid language: type-checking & code-generation
Benoît Caillaud – S4
21 March 2012 - 13
The non-standard semantics of hybrid systems
Benoît Caillaud – S4
21 March 2012 - 14
Industrial ties, impact,
competition & future
Benoît Caillaud
21 March 2012
Industrial ties & impact
Topic Impact
Contract-based design
Airbus/EADS, IAI
• 2 Pilot projects on Airbus applications
(part of the SPEEDS and CESAR
projects)
Hybrid modeling
Dassault Systems, Modelica
Consortium
• Contribution to Modelica design
meetings
• Discussions with DS
Benoît Caillaud – S4
21 March 2012 - 16
Competition & Cooperation
Topic Community / Applications
Contract-/interface-based design
Formal methods in computer science ……...(AA)
System engineering…………………………….(A)
Opacity control
DES control……………………….…………...(AA)
PN synthesis & applications
Formal methods in computer science ……(AAA)
Process mining…………………….……………(A)
Hybrid modeling
System / control engineering……………….....(A)
Benoît Caillaud – S4
21 March 2012 - 17
Future plans
S4 is not expected to continue after 2012.
New team proposal is under construction with researchers from
Vertecs/S4/Distribcom, led by Eric Fabre.
Objective: modeling, analysis & management of distributed heterogeneous systems
• distribution = modularity, composition, concurrency
• heterogeneity = quantitative aspects, as time, probabilities, costs, performance…
• analysis = verification, test
• management = control, diagnosis, planning, optimization…
Challenges:
• scale up to large / complex systems by abstractions, approximate analysis,
parameterization…
• handle reconfigurable, partially known, open systems
• design distributed/modular management methods: modularity, multi-agent, games
Applications:
• (large) open reconfigurable software (from embedded systems to web-services
and distributed active documents)
• (very) large structured systems: SoS, telecommunication network management
Benoît Caillaud – S4
21 March 2012 - 18
Future plans
High-level summary of research topics inherited from S4
(Petri-net theory: complete handbook on Petri-net synthesis: 01/2013)
Hybrid modeling:  Synchronics LSIA & Parkas team
• Non-standard semantics, type system and modular compilation of a
semi-explicit / algebraic synchronous hybrid modeling language
• Causality based partitioning of hybrid models; coupling numerical
solvers
• Contributing to the synchronous extension of the Modelica language
(Modrio & Sys2soft collab. projects)
Modal interfaces:
• (Complete survey for The Proc. of the IEEE: 06/2012)
• increase expressivity while preserving tractability.
• from natural language requirements to executable models.
Benoît Caillaud – S4
21 March 2012 - 19
Future plans
Data-centric workflow management systems:
• Opacity in documents
• Distributed active documents
• Applications to e-learning (LIRIMA)
Control & Games:
• Imperfect information cooperative game theory: tractable abstractions
of large distributed systems.
• Adversarial game theory: attack-defense trees synthesis for security
issues, control for privacy objectives in open systems (eg. social graphs).
• Logical foundations, automata-theoretical approaches, equilibria, …
Benoît Caillaud – S4
21 March 2012 - 20
Thank you