S4 S4 System Synthesis and Supervision, Scenarios Benoît Caillaud 20 March 2012.

S4System Synthesis and Supervision, Scenarios

Benoît Caillaud

20 March 2012

Benoît Caillaud – S4

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

21 March 2012 - 2


People & competences

21 March 2012 - 3

Eric Badouel Models of concurrency & Petri nets, Supervisory Control, Timed systems

Albert Benveniste Probability & statistics, Hybrid modeling

Benoit CaillaudModels of concurrency & Petri nets, Probability & statistics, Supervisory Control, Hybrid modeling, Tool Development

Philippe Darondeau

Models of concurrency & Petri nets, Supervisory Control, Timed systems

Axel Legay Probability & statistics, Timed systems

Sophie Pinchinat Logics & Games, Supervisory Control, Timed systems


Topics and major resultsContract-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

21 March 2012 - 4

Modal Interfaces

Benoît Caillaud 21 March 2012


Subsystem C

Component E

21 March 2012 - 6

Modal Interfaces: algorithmic foundation of (A,G) contracts

Specification algebra supporting:

• Contract-based design

• Independent implementability

• Multiple viewpoints

• Compositional reasoning

• Efficient algorithms

System A

Subsystem B

Component D

×

×<<

< <<

ContractB4

ContractB3

ContractB2

ContractE1

ContractB4

ContractB3

ContractB2

ContractD1

ContractB1

ContractB1

ContractB1

ContractC1

ContractB4

ContractB3

ContractB2

ContractB1

ContractB4

ContractB3

ContractB2

ContractA1≤?

≤?


Modal Interfaces

Deterministic I/O modal transition system: transitions are given

a label may or/and must

• may transitions are dashed

• must transitions are solid

• implementation: must everywhere

• refinement: simulation rel. strengthening must and weakening may

• extend Interface Automata, ~ conjunctive fragment μ-calculus,

• polynomial complexity (unlike μ-calculus) prototype tool Mica

21 March 2012 - 7

a b

nack!

ack!sent? nack!

sent?

ack!

f

A

sent?, overload?

overload?overload?


Modal Interfaces: algebraic properties

21 March 2012 - 8

Opacity control



Supervisory control for opacity in open systems

21 March 2012 - 10


Concurrent Secrets

21 March 2012 - 11

Hybrid Modeling



The non-standard semantics of hybrid systems

21 March 2012 - 13

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


The non-standard semantics of hybrid systems

21 March 2012 - 14

Industrial ties, impact, competition & future



Industrial ties & impact

Topic

Contract-based design

Hybrid modeling

Impact

Airbus/EADS, IAI

• 2 Pilot projects on Airbus applications (part of the SPEEDS and CESAR projects)

Dassault Systems, Modelica Consortium

• Contribution to Modelica design meetings

• Discussions with DS

21 March 2012 - 16


Competition & Cooperation

Topic

Contract-/interface-based design

Opacity control

PN synthesis & applications

Hybrid modeling

Community / Applications

Formal methods in computer science ……...(AA)System engineering…………………………….(A)

DES control……………………….…………...(AA)

Formal methods in computer science ……(AAA)Process mining…………………….……………(A)

System / control engineering……………….....(A)

21 March 2012 - 17


Future plansS4 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

21 March 2012 - 18


Future plans

(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.

21 March 2012 - 19

High-level summary of research topics inherited from S4


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, …

21 March 2012 - 20

Thank you

S4 S4 System Synthesis and Supervision, Scenarios Benoît Caillaud 20 March 2012.

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Transcript of S4 S4 System Synthesis and Supervision, Scenarios Benoît Caillaud 20 March 2012.