Coupled Simulations Using different Tools Dag Fritzson MODPROD Workshop 2007-02-07 2007-03-13 SKF Slide 1 MODPROD Contents Why coupled simulations? - Problem definition Meta-Modelling TLM Co-Simulation & Framework Examples Conclusion 2007-03-13 SKF Slide 2 MODPROD 2007-03-13 SKF Slide 1 [Code] SKF [Organisation]
1Why coupled simulation - Problem definition 2007-03-13 SKF Slide 3 [Code] SKF [Organisation] Problem Definition MSC.ADAMS BEAST Modelica Facts: Large investment in specialized tools No universal tool solves everything One Possibility: Coupled simulation Ansys Questions on the Way: How to couple different simulation models? How to model coupled simulations? How organize models of coupled simulation models? 2007-03-13 SKF Slide 4 MODPROD 2007-03-13 SKF Slide 2 [Code] SKF [Organisation]
Application Example Car With Hub-unit BEAST hub-unit model BEAST allows for detailed contact analysis in the wheel Bearings. MSC.ADAMS car model MSC.ADAMS allows for analysis of chassis and body dynamics. Hub-unit placed in front wheel 2007-03-13 SKF Slide 5 MODPROD A car and SKF hub unit 2007-03-13 SKF Slide 6 MODPROD 2007-03-13 SKF Slide 3 [Code] SKF [Organisation]
Using Co-Simulation for Connecting Tools Co-simulation is a well known technique. However: How to model coupled simulations? How to make co-simulation modeling easy to use? Many co-simulation applications focus on control-system applications, e.g., hardware in the loop. Our focus is on coupling different mechanical system simulations. This puts special requirements on the modeling process, i.e., general interface for force and motion exchange and 3D component modeling. 2007-03-13 SKF Slide 7 MODPROD 2Meta-Modelling 2007-03-13 SKF Slide 8 [Code] SKF [Organisation] 2007-03-13 SKF Slide 4 [Code] SKF [Organisation]
Meta-Model Definitions A meta-model here defines the physical interconnections combining different external component models An external model is a model defined in some specific modeling language together with some modeling and simulation tool that can perform a simulation of it. Meta-Model: BEAST model Modelica model MSC.ADAMS model 2007-03-13 SKF Slide 9 MODPROD The Complete Modelling Process Modeling in specialized environment Define interface points and encapsulate model Meta-modeling Sim. tool specialists Sim. tool specialists and/or meta-model designers Meta-model designers 2007-03-13 SKF Slide 10 MODPROD 2007-03-13 SKF Slide 5 [Code] SKF [Organisation]
Component Encapsulation for Meta-Modeling Simple easy-to-use graphical user interface (wizard) Automated TLM interface detection (requested from simulation model) Component encapsulation for improved component reusability and exchange 2007-03-13 SKF Slide 11 MODPROD Meta-Model Editor (MME) Features/requirements: Easy simulation model integration 3D view of all meta-model components Automated physical TLM interface alignment Visual connection verification 2007-03-13 SKF Slide 12 MODPROD 2007-03-13 SKF Slide 6 [Code] SKF [Organisation]
3TLM Co-Simulation & Framework 2007-03-13 SKF Slide 13 [Code] SKF [Organisation] Transmission Line Model Physical time delay for force waves The physical delay is used to decouple equations Numerically stable method 2007-03-13 SKF Slide 14 MODPROD 2007-03-13 SKF Slide 7 [Code] SKF [Organisation]
TLM Theory Mechanical Delay Line c 2 (t) = F 1 (t-t TLM ) + Z F v 1 (t-t TLM ) v 1 v 2 F 1 (t) = Z F v 1 (t) + c 1 (t) c 1 (t) = F 2 (t-t TLM ) + Z F v 2 (t-t TLM ) F 2 (t) = Z F v 2 (t) + c 2 (t) Passing wave variables c 1, c 2 Velocity variables v 1, v 2 Force variables F 1, F 2 Time delay in the line T TLM Line impedance Z F 2007-03-13 SKF Slide 15 MODPROD Meta-Model Simulation Environment System Design Meta-Models are stored in a Meta-Model-Language (MML) file The TLM-Manager executes and organizes the Co- Simulation MMS results can be visualized (animated) in MME post-processing mode The Simulator starts the TLM- Manager and stores Meta-Model Simulation (MMS) results 2007-03-13 SKF Slide 16 MODPROD 2007-03-13 SKF Slide 8 [Code] SKF [Organisation]
TLM Co-Simulation in Practice - TLM Manager TLM Manager controls the cosimulation Narrow and efficient interface for the tools Use a meta model that defines Which external-models are involved How are they connected (name of points) Start, stop, time step and TLM parameters BEAST TLM Manager ADAMS 2007-03-13 SKF Slide 17 MODPROD TLM Framework A general framework has been defined that can be implemented in many different simulation tools. It has successfully been implemented and tested for: MSC.ADAMS (Released) Matlab-Simulink Modelica BEAST (SKF) (Released) Orpheus (SKF) 2007-03-13 SKF Slide 18 MODPROD 2007-03-13 SKF Slide 9 [Code] SKF [Organisation]
3Examples 2007-03-13 SKF Slide 19 [Code] SKF [Organisation] Verification Meta-Model A simulation model has been designed to verify TLM cosimulations The model is simple and contains all important features to test the complete TLM framework. 2007-03-13 SKF Slide 20 MODPROD 2007-03-13 SKF Slide 10 [Code] SKF [Organisation]
Running the Verification Meta-Model The verification meta-model has been created and tested for different simulation tool combinations. NOTE: Some tools, e.g., Simulink cannot create VRML files for visualization in MME. Simulink-BEAST-Simulink 2007-03-13 SKF Slide 21 MODPROD Example: Single Pendulum Pendulum beam in ADAMS 1) Frictionless joint in ADAMS 2) Support DGBB in BEAST Results similar Friction in the DGBB brake a little 2007-03-13 SKF Slide 22 SKF [ERC] 2007-03-13 SKF Slide 11 [Code] SKF [Organisation]
Example: Single Pendulum Results Pendulum beam in ADAMS 1) Frictionless joint in ADAMS 2) Support DGBB in BEAST Results similar Friction in the DGBB brake a little 2007-03-13 SKF Slide 23 SKF [ERC] Example: Modelica TLM Plug-in Comparing a BEAST-Modelica Meta-Model simulation with a pure Modelica model simulation. TLM BEAST shaft Inertia1 J=6.26 2007-03-13 SKF Slide 24 MODPROD 2007-03-13 SKF Slide 12 [Code] SKF [Organisation]
Example: ADAMS Spindle with two BEAST bearings 2007-03-13 SKF Slide 25 MODPROD Results: ADAMS Spindle with two BEAST bearings Splindle position affected by bearings 2007-03-13 SKF Slide 26 MODPROD 2007-03-13 SKF Slide 13 [Code] SKF [Organisation]
Astra car and SKF hub unit Complete car model in ADAMS Hub unit in BEAST connects the knuckle with the wheel 2007-03-13 SKF Slide 27 SKF [ERC] Astra car and SKF hub unit - Animations 2007-03-13 SKF Slide 28 MODPROD 2007-03-13 SKF Slide 14 [Code] SKF [Organisation]
Astra car and SKF hub unit MME Animation Results can be visualized in MME postprocessing mode 2007-03-13 SKF Slide 29 MODPROD Conclusions Coupled simulations needed in industry Easy to do meta-modelling process Support many tools, easy to add new Stable simulations Starting to be used in SKF Issues: Company wide coupled simulations possible or practical? 2007-03-13 SKF Slide 30 MODPROD 2007-03-13 SKF Slide 15 [Code] SKF [Organisation]
2007-03-13 SKF Slide 16 [Code] SKF [Organisation]