The OMG SysML-Modelica Transformation Specification · SysML-Modelica Transformation Specification Transformations in Model-Based Systems Modeling Summary. Acknowledgements Working

The OMG SysML-Modelica Transformation Specification:Supporting Model-Based Systems Engineering

Model-Based Systems Engineering Center

1MBSE2008-2011 Copyright © Georgia Tech. All Rights Reserved.

Supporting Model-Based Systems Engineeringwith SysML and Modelica

Chris ParedisAssociate DirectorModel-Based Systems Engineering CenterGeorgia [email protected]

www.pslm.gatech.edu/courseswww.omg.org/ocsmp

SysML-Modelica Transformation Specification:Context & Objective

� Two complementary languages for Systems Engineering:– Descriptive modeling in SysML– Formal equation-based modeling for

analyses and trade studies in Modelica

Objective:


� Objective:– Leverage the strengths of both SysML and Modelica by

integrating them to create a more expressive and formal MBSE language.

– Define a formal Transformation Specification:» a SysML4Modelica profile» a Modelica abstract syntax metamodel» a mapping between Modelica and the profile

Presentation Overview

� What is SysML?� What is Modelica?

� Motivating Example: Design & Analysis of Robot


� SysML-Modelica Transformation Specification� Transformations in Model-Based Systems Modeling� Summary

Acknowledgements

Working Group Members� Yves Bernard (EADS)� Roger Burkhart (Deere & Co)� Wuzhu Chen (Univ. Braunschweig)� Hans-Peter De Koning (ESA)� Sandy Friedenthal (Lockheed

Martin)

Students / post-docs� Kevin Davies� Sebastian Herzig� Alek Kerzhner� Ben Lee� Roxanne Moore

Axel Reichwein


Martin)� Peter Fritzson (Linköping University)� Nerijus Jankevicius (No Magic)� Alek Kerzhner (Georgia Tech)� Andreas Korff (Atego)� Chris Paredis (Georgia Tech)� Axel Reichwein (Georgia Tech)� Nicolas Rouquette (JPL)� Wladimir Schamai (EADS)

� Axel Reichwein� Wladimir Schamai

Sponsors� Deere & Co� Lockheed Martin� National Science

Foundation

Systems Modeling Language: SysML

� SysML is an extension of the Unified Modeling Language.

� Supports the modeling of physical systems – not just software


software

� It is not a methodology or tool

� Improves the ability to exchange systems engineering informationamong tools and people

definition

bdd [package] VehicleStructure [ABS-Block Definition Diagram]

«block»Traction Detector

«block»Brake

Modulator

«block»Library::Electro-Hydraulic

Valve

«block»Library::

Electronic Processor

«block»Anti-Lock Controller

d1 m1

Pillars of SysML: 4 Main Diagram Types

1. Structure 2. Behavior

(Source: Friedenthal, www.omgsysml.org)


definition

4. Requirements 3. Parametrics

definition



«block»Brake

Modulator


Valve

«block»Library::



d1 m1

use

ibd [block] Anti-LockController [Internal Block Diagram]

d1:Traction Detector

m1:Brake

c1:modulator interface


1. Structure 2. Behaviorsd ABS_ActivationSequence [Sequence Diagram]

d1:TractionDetector

m1:BrakeModulator

detTrkLos()

modBrkFrc()

sendSignal()

modBrkFrc(traction_signal:boolean)

interaction



definition use m1:Brake Modulator


sendAck()

definition



«block»Brake

Modulator


Valve

«block»Library::



d1 m1

use



m1:Brake




d1:TractionDetector

m1:BrakeModulator

detTrkLos()

modBrkFrc()

sendSignal()


interaction

state machine

stm TireTraction [State Diagram]

Gripping Slipping

LossOfTraction

RegainTraction





sendAck()

definition



«block»Brake

Modulator


Valve

«block»Library::



d1 m1

use



m1:Brake




d1:TractionDetector

m1:BrakeModulator

detTrkLos()

modBrkFrc()

sendSignal()


interaction

state machine

stm TireTraction [State Diagram]

Gripping Slipping

LossOfTraction

RegainTractionactivity/function

act PreventLockup [Activity Diagram]

DetectLossOf Traction

Modulate BrakingForce

TractionLoss:



req [package] VehicleSpecifications [Requirements Diagram - Braking Requirements]

Braking Subsystem Specification

Vehicle System Specification

id=“102”text=”The vehicle shall stop from 60 mph within 150 ft on a clean dry surface.”

«requirement»StoppingDistance

id=”337"text=”Braking subsystem shall prevent wheel lockup under all braking conditions.”

«requirement»Anti-LockPerformance

«deriveReqt»



sendAck()

par [constraintBlock] StraightLineVehicleDynamics [Parametric Diagram]

:AccellerationEquation[F = ma]

:VelocityEquation[a = dv/dt]

:DistanceEquation[v = dx/dt]

:BrakingForceEquation

[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:



Modulate BrakingForceTractionLoss:



m1:Brake Modulator


Cross Connecting Model Elements1. Structure 2. Behavior

act PreventLockup [Swimlane Diagram]

«allocate»:TractionDetector

«allocate»:BrakeModulator

allocatedTo«connector»c1:modulatorInterface



TractionLoss:










«deriveReqt»






[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:







m1:Brake Modulator









TractionLoss:


allocatedFrom«activity»DetectLosOfTraction

d1:TractionDetector

allocatedFrom «activity»Modulate BrakingForce

m1:BrakeModulator

allocatedFrom«ObjectNode»TractionLoss:

c1:modulatorInterface










«deriveReqt»






[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:







m1:Brake Modulator









TractionLoss:



d1:TractionDetector


m1:BrakeModulator





d1:TractionDetector


m1:BrakeModulator



satisfies«requirement»Anti-LockPerformance










«deriveReqt»






SatisfiedBy«block»Anti-LockController



«deriveReqt»






[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:


satisfy






m1:Brake Modulator









TractionLoss:



d1:TractionDetector


m1:BrakeModulator





d1:TractionDetector


m1:BrakeModulator





allocatedFrom«activity»DetectLosOf Traction

d1:TractionDetector

valuesDutyCycle: Percentage


m1:BrakeModulator













«deriveReqt»









«deriveReqt»






[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:







[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

m:

a:a:

v:

v:

x:

v.Position:

v.Weight:v.chassis.tire.Friction:

v.brake.abs.m1.DutyCycle:

v.brake.rotor.BrakingForce:

satisfy






m1:Brake Modulator









TractionLoss:



d1:TractionDetector


m1:BrakeModulator





d1:TractionDetector


m1:BrakeModulator





allocatedFrom«activity»DetectLosOf Traction

d1:TractionDetector

valuesDutyCycle: Percentage


m1:BrakeModulator













«deriveReqt»









«deriveReqt»






[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

c

a:a:

v:

v:

x:







[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

m:

a:a:

v:

v:

x:

v.Position:









[f = (tf*bf)*(1-tl)]

tf: bf:tl:

f:

F:

m:

a:a:

v:

v:

x:

v.Position:







VerifiedBy«interaction»MinimumStoppingDistance






«deriveReqt»

satisfy

What is Modelica?(www.modelica.org)

� State-of-the-art Modeling Languagefor System Dynamics– Differential Algebraic Equations (DAE)– Discrete Events


� Represents DAE models in an object-oriented, engineering-oriented language

� Multi-(physical)-domain modeling� Ports represent energy flow (undirected) or

signal flow (directed)� Acausal, equation-based, declarative (f-m*a=0)

Modelica Semantics and Textual Syntax

spring1


� Connections represent Kirchhoff semantics– Across variables (voltage, pressure,…) are equal– Through variables (current, flow rate,…) add to zero

mass1

m=1

spring1 fixed1

Graphical symbols defined as annotations in textual models






A Robot Example in Modelica


mot

or to

rque

SysML-Modelica Robot Example:UseCases & Requirements


SysML-Modelica Robot Example:Robot Domain BDD & IBD


SysML-Modelica Robot Example:Robot BDD & IBD

21MBSE2008-2011 Copyright © Georgia Tech. All Rights Reserved.Presentation for the INCOSE Symposium 2010 Chicago, IL USA

SysML-Modelica Robot Example:Robot Arm BDD


SysML-Modelica Robot Example:Analysis and Trade Study


Analysis models depend on descriptive models

Drag and drop intoIBD «ModelicaModel»

SysML4Modelica Analytical Model:Compose Model from Standard Library


SysML4Modelica Analytical Model:Detailed IBD


SysML4Modelica Analytical Model:Detailed IBD


SysML4Modelica Analytical Model:Relation to Modelica Native Model


SysML-Modelica Robot Example:Modelica model with simulation results


SysML-Modelica Robot Example:Analysis and Trade Study


Analysis results are incorporated in Trade Study

SysML-Modelica Robot Example:An Analysis Context


SysML-Modelica Robot Example:Dependencies between Models


SysML-Modelica Robot Example:Dependencies between Models







Model Transformation

Source Metamodel

Source Model

Target Metamodel

Target Model

conforms to conforms to

Transformation Specification

Transformation Enginereads writes

refers to refers to

executes

(Czarnecki, K., & Hellen, S., 2006)


� Model Driven Architecture / Engineering� Transformation Specification = Model� automated generation of transformation engine code

� Tools: MOFLON, QVTo, ATL, Kermeta, VIATRA2, …

SysML-Modelica Transformation Specification

SysML-Modelica

Transformation follows the


follows the principlesof Model-

Driven Architecture

(MDA)

SysML4Modelica Profile


ModelOverviewComponents[Package] bdd [ ]

<<ModelicaPort>>flange_a : Flange

<<ModelicaPort>>flange_b : Flange

<<ModelicaModel>>ModelicaStandardLibrary::Mechanics::Translational::Interfaces::

PartialCompliant {s_rel = flange_b.s - flange_a.s; flange_b.f = f;

flange_a.f = -f;}

<<ModelicaValueProperty>>+s_rel : Distance<<ModelicaValueProperty>>+f : Force

<<ModelicaPort>>flange_a : Flange

<<ModelicaPort>>flange_b : Flange

<<ModelicaExtendsRelation>>

SysML4Modelica


<<ModelicaModel>>ModelicaStandardLibrary::Mechanics::Translational::Components::

Spring{f = c*(s_rel - s_rel0);}

<<ModelicaValueProperty>>+c : TranslationalSpringConstant{variability = parameter}<<ModelicaValueProperty>>+s_rel0 : Distance{variability = parameter}

Modelica

For

mal

m

appi

ng

Reference implementation:Based on OMG QVT

Modelica abstract

XMI(SysML4

conforms toSysML+

SysML4Modelicametamodel

SysML Tool

XMI(Modelica)

conforms toModelica

metamodel


syntaxModelica)Tool

Modelica.mo file

Tool-Specific Repository

QVT(normative)

(Modelica)

OMC

QVT = Query / View / Transformation






D

D

Model Transformations in MBSE

DD

DD

D

D

DD

Model Object

D Model Dependency


D

DD

DD

DDD

D

D

D

D

DD

D

D

DD

D

D

System Model

D

D

Model Transformations in MBSE:Federated Models

DD

DD

D

D

SysMLProfile

A

ProfileB

D

D

DD

Domain ATool B

Model Object

D Model Dependency


D

DD

DD

D

D

D DD

D

D

DD

D

D

SysMLA

ProfileC

Profile D

Tool D

Domain C

System Model

Model Transformations in MBSE

Requirements

FormalSystemModel

Stage-Gate Documents

Transformation


Project Management Metrics

Transformation

Verification & ConsistencyManagement

Model Transformations in MBSE:Reusable Models

Requirements


Revision by GIT; Original Source: OMG SysML Tutorial (June 2008). Reprinted with permission. Copyright © 2006-2008 by Object Management Group.

Creating Models is Expensive and Time-Consuming

Model Transformations in MBSE:Applying Reuse Patterns

� Physical components are reused� Portions of the system model repeat� Patterns for instantiating these portions


� Component models � Domain specific model libraries� Application of pattern = model transformations

Electric Motors


� When cylinder is used, other corresponding models are often used also

� Capture the reuse pattern




Model Transformations in MBSE:Descriptive to Analytical Transformation

SysMLDescriptive

SysML4Modelica


DescriptiveModels

CorrespondenceModels

AnalyticalModels

SysML4ModelicaAnalytical

SysML

Model Transformations in MBSE:Architecture Exploration

Problem Definition

Generate Architecture

ComponentsSysML

SysML Model exchanged in XMIMagicDraw SysML Editor

GAMS SolverTransformation Engine

Topology Analysis

Variable FidelityModel Selection


SysML

SysML

GenerateAlgebraic Design

Problem

SysMLAlgebraic Models

GenerateDynamic Design

Problem

SysMLDynamic Models

Problem Formulation Problem Solution

Analysis

Dynamic Analysis

Uncertainty Quantification

Mixed-IntegNonlin Solver

Algebraic Analysis

OptimizationSolver

Monte Carlo + KrigingDesign Explorer Modelica

GAMS

Summary

� Objective:– Leverage the strengths of both SysML and Modelica by

integrating them to create a more expressive and formal MBSE language.


Descriptive Modeling in SysML+

Formal Equation-Based Modeling forAnalyses and Trade Studies in Modelica

http://www.omg.org/spec/SyM/