with standardization to flexibility: functional mock-up interface (fmi) simplifies the world of...

With Standardization to Flexibility Functional Mock-up Interface (FMI) simplifies the World of Co-Simulation

European Altair Technology Conference 2014

Ronald Kett, FLUIDON GmbH

FLUIDON – Who We are

FLUIDON is an engineering company specialized on fluid power mechatronic systems

Founded in 1994 as a spin-off of Institute of Fluid Power (RWTH Aachen)

Simulation of mechatronic systems is the key competence of FLUIDON engineers

That means support in the complete area of system development and application

provision of simulation software

software services

engineering support

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What are the Characteristics of DSHplus-STC?

Motivation

Due to increasing demands of realism and calculation accuracy, it is more and more necessary to

consider the interactions of different technical subsystems in simulation studies in detail.

By coupling of programs with different strengths, the advantages of all programs can be used by a

simulation in a software network.

Realization

The DSHplus STC is a push-button solution for seamless coupling and integration of one-

dimensional domain-cross DSHplus models with arbitrary CAx tools..

In addition to classic co-simulation solutions, the DSHplus STC EcoSim - Embedded Co-simulation

– offers an enclosed and protected stand-alone module, which includes both the one-dimensional

DSHplus model, as well as the co-simulation interface and the DSHplus calculation core.

As a third type a coupling on equation level is supported. The differential and algebraic equations

of DSHplus model are calculated by the solver of the Master Simulator.

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The Principle of DSHplus-STC

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Step 2: Optimization and Verification of the fluid power System by means of a co-simulation

DSHplus Co Simulation

Step 1: Initial simulation of the fluid power system in DSHplus

Step 3: Export of the fluid power system as embedded system in a different simulation domain or on a different hardware

C++ ModelSource Code

C++ AuxiliaryFunctions

C++ NumericalRoutines

DSHplus DifferentialEquation Export

DSHplus Solver Export

Milestones of DSHplus-STC

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Equation

export

to ACSL

Air-Spring

co-simulation

with SIMPACK

Equation

export

to ADAMS

Co-simulation

with MOBILE

Equation

export

to Simulink

Equation

export

to Opal-RT

Program launch

directly with open

source code

model description

FLUIDON

joined MATLAB

partner program

FLUIDON joined

Launch of

-STC

-STC

for SIEMENS

WinAC Soft PLC

ADAMS Plug-In

for -STC

-STC

for KIVA

combustion

simulation

Interface with

1996 1998 2010 2002 2004 2006 2008 2000 1994 2012 2014 1973

DSH program

roots at

RWTH Aachen

Hardware

interfacing with

Programmable

Logic Controller

Interface

FMI

Engine

with ECU Gearbox with ECU

Thermal systems

Automated cargo door

Chassis components, roadway, ECU (e.g. ESP)

etc.

Source: Daimler AG

functional mockup interface for model exchange and tool coupling

What the Hell is FMI?

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in general terms, FMI continues the STC outside of DSHplus

additional interface functions extend and generalize the field of application

FMI is the result of the European MODELISAR research project 2008 - 2011, in Germany

under leadership of Daimler AG.

The following slides originate from the presentation „The Functional Mockup Interface for

Tool independent Exchange of Simulation Models“, which was held at the end of the

research project MODELISAR at Modelica Conference 2011.

By the way, Mathworks does not take part in FMI-standard, because Matlab itself is

considered as a standard. But several third-party suppliers developed tool boxes, with

which FMU can be used in Simulink.

FMI – Main Design Idea

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FMI for Model Exchange:

Version 1.0 released in January 2010

FMI for Co-Simulation:

Reuses as much as possible from FMI for Model Exchange standard

Version 1.0 released in October 2010

Tool

Solver

FMU

Model

Tool

FMU

Model

Solver

Source: Modelica 2011: Functional Mockup Interface

FMI - Main Design Idea

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A component which implements the interface is called

Functional Mockup Unit (FMU)

Separation of

Description of interface data (XML file)

Functionality (C code or binary)

A FMU is a zipped file (*.fmu) containing

XML description file

implementation in source or binary form

Additional data and functionality

Additional data and functionality can be included

Interface specification: www.functional-mockup-interface.org

FMI for Model Exchange

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Import and export of input/output blocks (FMU – Functional Mock-up Unit)

described by

differential-, algebraic-, discrete equations,

with time-, state, and step-events

FMU can be large (e.g. 100000 variables)

FMU can be used in an embedded system (small overhead)

FMUs can be connected together

FMI for Model Exchange

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Signals of an FMU

FMI for Co-Simulation

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Master/slave architecture

Considers different capabilities of simulation tools

Support of simple and sophisticated coupling algorithms:

Iterative and straight forward algorithms

Constant and variable communication step size

Allows (higher order) interpolation of continuous inputs

Support of local and distributed co-simulation scenarios

FMI for Co-Simulation does not define:

Co-simulation algorithms

Communication technology for distributed scenarios

FMI for Co/Simulation

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Signals of an FMU for Co-Simulation

Inputs, outputs, and parameters, status information

Derivatives of inputs, outputs w.r.t. time can be set/retreived for supporting of higher order approximation

u y

Enclosing Model

v 0 0 0 0 0 0, ,inital values (a subset of { , , , , })t p x x y v m

Co-Simulation Slave (FMU instance)

t

Model

Solver

Co-Simulation Master

t0, p


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Use Case


Co-Simulation stand alone:

Co-Simulation tool:

Process

Executable Library (DLL)

Slave

Model Solver

Slave

Model Solver Master

Process 1

Executable Library (DLL)

Process 2

Simulation tool

Slave

Model Solver

FMI

Wrapper

FMI

Wrapper

FMI

Wrapper

FMI

Wrapper Master


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Use Case


Distributed co-simulation scenario

Data exchange is handled by a communication layer which is implemented by a special FMI

wrapper

Master and slave utilize FMI for Co-Simulation only

Who supports FMI?

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A standard is certainly as good as its

application.

Since the initiation of FMI the list of FMI

supporter comprises 58 programs that

support or plan to support FMI.

This list is maintained on www.fmi-

standard.org.

FLUIDON presently supports FMI for Co-

Simulation both as classic Co-Simulation

(tool) and as ECoSim (embedded Co-

Simulation) (stand alone) for Windows 32bit

and 64bit.

In the future DSHplus will support also FMI

for Model Exchange and Linux versions.

Is FMI supported within Altair Tools?

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The new Scicos Pro offers an interface according to FMI 2.0.

Thank you for your attention.

with standardization to flexibility: functional mock-up interface (fmi) simplifies the world of...

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