Post on 26-Mar-2015
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Universität PaderbornAG Softwaretechnik
Towards Modular Modeling and SimulationTowards Modular Modeling and Simulationof Production Control Systemsof Production Control Systems
Holger GieseHolger Giese und Ulrich A. Nickel und Ulrich A. NickelAG Softwaretechnik, Universität PaderbornAG Softwaretechnik, Universität Paderborn
Warburger Str. 100, 33098 PaderbornWarburger Str. 100, 33098 Paderborn{hg|duke}@upb.de{hg|duke}@upb.de
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 2/15
Production Control System Executable UML Class Model & Simulation Modularity & Separation for Executable Models Requirements & Simulation Conclusion & Future Work
Overview
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 3/15
Production Control System (PCS)
Flexible distributed control is „complex” to build
Frequent adaptation to new requirements or changes in the topology are required
Programming languages (Ada, C, …)
Test & code corrections in the production environment
Design and maintenanceMethodology & UML
Avoid long downtimes Verification is hard problem
Simulation
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 4/15
Application SoftwareGate
Bus Interface
Sensors/Actors
Processor Nodes ID Identification Unit
Data Links St Stopper
Travel Direction M Motor
Signal Direction S Sensor
ID St MS
S
PCS: Overview & Elements
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 5/15
Executable UML Class Model
UML Model describes: possible system
topology Reactive overall
class behavior (Statecharts, SDL,..)
Advantages: OO concepts: e.g.,
class encapsulation Visual modeling High level viewSignal
Gate
Track
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 6/15
Specification
Topology
Visuali-zation
Simulation
Control software
Simulation kernel
Java Virtual Machine
JavaReflect
Dobs
Production-order
Codesynthesis
Hardwareconfiguration
Executable UML Model Simulation
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 7/15
Classes & Simulation
Simulation result: Can detect coordination
problems: deadlock, … Provides insight into
system dynamics (tinkering style)
Limitations: System has to be
complete (closed) Observations do only hold
for very restricted form of subclass refinement
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 8/15
Modularity: Overall Synchronization
Component Spec.: overall behavior arbitrary structuresAbstraction: combine processes build abstract process behavior for layer C depends on (A || B) no abstraction barrier for used layersLimitations: State explosion problem (propability for error
detection) Component exchange preserve results only when
very restricted conformance realtion holds
A
B
C
Layer C
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 9/15
Modularity: Contract
Reduce class behavior to external visible/relevant contract behavior
Multiple contracts (UML-RT ports)
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 10/15
Modularity: Partial Contract Border
Component Spec.: set of contract behavior layered structures
Abstraction: specification for layer
C is C1 || ... || C4 partial model simulation & analysis
arbitrary usage of provided contracts C5 || C6 || C7 assumed for used contracts
Limitation: embedding restricted to layered structures
C1
C2
C3
C4
C7
C6
C5
Contracts are design elements, but the by abstraction steps derived abstract
processes are not!!
Layer C
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 11/15
Modularity: Open PCS
Factory as open system within and out contracts (ports): possible Environments? embedding?
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 12/15
Modularity: Implicit Component Behavior
support even for set of contract behavior
and implicit dependencies Embedding only restricted
by demand to ensure acyclic dependencies
Abstraction: specification for C1, …, C4
Advantage: More flexible embedding when independent
C1
C2
C3
C4
C7
C6
C5
Component C
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 13/15
Modularity: Implicit Component Behavior
Open factory with implicitcomponent behavior: implicit environment embedding rule:
“depend has to remain acyclic”
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 14/15
Requirements & Simulation
Requirements are describedScenario-oriented: external view system may realize
suitable interleaving for multiple parallel requested tasks
Factory Simulation: use for checking use for run-time
assertions
Universität PaderbornAG Softwaretechnik
Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems 15/15
Conclusion & Future Work
Modeling PCS: strong requirements for control
software methodology & UML-RT code synthesis and simulation (partial)Validation via simulation: early failure detection interactive “testing”Modular simulation improved separation modularity & scalability
Future Work
• Realize extended concept
• Integrate time support