DoE & Optimization in Automotive MBS Simulation Tasks

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DoE & Optimization in Automotive MBS Simulation Tasks

  1. 1. DoE & Optimization in Automotive MBS Simulation Tasks 2011 European HyperWorks Technology Conference, Nov. 8th, Bonn, Germany8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 1
  2. 2. Application of MBS Suspension Analysis Comfort & Simulation Vehicle Handling Consistent Mechatronic Vehicle Model mechatronic component Calculation of Calculation of Static & Dynamic Package Demand Loads8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 2
  3. 3. Content 1. Introduction and calculation process • Initial point & mission • Process overview • Used software 2. Example: driving comfort design of engine mount systems • Problem definition • Engine mount system creation of coupled / decoupled variants • Relative comparison of different variants • Summary 3. Conclusions and further work8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 3
  4. 4. Initial PointMission (some years ago):Highlight the influence of vehicleconfigurations and testing parameters torollover behaviour. Long time running simulation. Huge number of simulation runs. Automated simulation and data analysis process needed.8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 4
  5. 5. Process Overview Parameters MBS Model Manoeuvres User defined Vehicle Configurations MBS Solver Module Properties Component Properties Data Analysis Results8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 5
  6. 6. Process Overview Parameters MBS Model Stochastic approach Manoeuvres DoE User defined Systematic approach Vehicle Configurations MBS Solver Module Properties Numerical Optimization optimization Component Properties Data Analysis Optimization Results DoE Correlation Coefficients8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 6
  7. 7. Used Software ALTAIR Hyperstudy® MSC.ADAMS/Car® Parameters MBS Model Stochastic approach Manoeuvres DoE User defined Systematic approach Vehicle Configurations MBS Solver Module Properties Numerical Optimization optimization Component Properties Data Analysis Python® Optimization Results DoE Correlation Coefficients National Instruments - DIAdem®8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 7
  8. 8. Content 1. Introduction and calculation process • Initial point & mission • Process overview • Used software 2. Example: driving comfort design of engine mount systems • Problem definition • Engine mount system creation of coupled / decoupled variants • Relative comparison of different variants • Summary 3. Conclusions and further work8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 8
  9. 9. Problem Definition Increased relevance of engine mount system design due to: • trend towards lighter car bodies (body in white) and more power-intensive engines • trend towards 3Zylinder / 2Zylinder engines engine torque fluctuation gets more important • front wheel driven vehicles with low idle speed Investigations considering the design & analysis of engine mount systems: • engine rigid body modes ( frequencies, coupling of modes) • engine excitation (gas forces acceleration at seat rail and mount positions at body) • road excitation ( acceleration at seat rail and mount positions at body)8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 9
  10. 10. Engine Mount System Is it possible to use the modal coupling as a reliable indicator of the performance of an engine mount system? Hypothesis: • Decoupling of engine rigid body modes increases comfort for engine excitation • Coupling of engine rigid body modes increases comfort for road excitation Finding coupled & decoupled engine mount systems by means of DoE and numerical optimization by using modal kinetic energy Calculation of engine and road excitations and judge accelerations at seat rail and body- sided mount positions8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 10
  11. 11. Definition of Modal Kinetic Energy Modal matrix with Eigenvectors Reduced modal matrix considering degrees of freedom of part j Modal kinetic energy of mode i Modal kinetic energy of part j considering mode i Thereby is the ith column vector of the reduced modal matrix 100% Modal kinetic energy of part “engine” 90% separated for six rigid-body engine modes 80% rz (number 31...36) and in translational & 70% 60% ry rotational directions. rx 50% z 40% y Result of a first DoE is a strongly coupled 30% 20% x version of engine mount system 10% 0% 33 32 31 35 34 368.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 11
  12. 12. Optimization Loop Optimization criteria is maximum of purity for each mode by using modal kinetic energy values Parameters: mount positions, mount stiffness and damping values Algorithm: ARSM Calculation time: ~17min 100% 90% Result of numerical optimization is a well 80% rz decoupled version of engine mount system, 70% ry regarding rigid-body engine modes 60% rx 50% z 40% y 30% x 20% 10% 0% 1 2 3 4 5 68.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 12
  13. 13. Engine / Road Excitation coupled decoupled MSF rough road + - Public highway + - Rough asphalt + - Cobblestone + - Result of virtual road simulation pavement Single obstacle + - Acceleration at driver seat rail (vertical direction) 3rd gear runup - + Relative comparison of different variants Idle run - +8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 13
  14. 14. Engine / Road Excitation versions with comparable versions with same basic frequencies stiffness / loss angle coupled decoupled coupled decoupled coupled decoupled coupled decoupled FRQ FRQ STIFF STIFF ½ STIFF ½ STIFF MSF rough road + - ~ ~ + - Public highway + - + - + - Rough asphalt + - ~ ~ + - Cobblestone pavement + - + - + - Single obstacle + - ~ ~ + - 3rd gear runup - + - + + - - + Idle run - + - + - + - +8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 14
  15. 15. Summary – Engine Mount System Design Conclusion: Shown results support Hypothesis: • Even if considering comparable rigid engine/gearbox pitch frequency (RY) or comparable stiffness levels: decoupling decreases body-accelerations for engine excitation coupling decreases body-accelerations for road excitation • Using modal kinetic energies offers possibility to tune an engine mount system as desired (improve comfort for road- or engine-excitation) in a very fast way • With additional boundaries (e.g. eigenfrequency of engine pitch mode should be low) optimized compromise solutions are possible8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 15
  16. 16. Content 1. Introduction and calculation process • Initial point & mission • Process overview • Used software 2. Example: driving comfort design of engine mount systems • Problem definition • Engine mount system creation of coupled / decoupled variants • Relative comparison of different variants • Summary 3. Conclusions and further work8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 16
  17. 17. Conclusions and further work Conclusion: • “Automated” simulation process successfully launched. • For different areas of MBS application at MAGNA Steyr, e.g. comfort simulation design of engine mount systems the application of numerical DoE and optimization methods certainly offers the possibility to accelerate the design process significantly. • Nevertheless the “push the button and get the optimal design” approach seems to be out of reach. Further work: • “Plug-and-play” process for mechatronic models (by using co-simulation MATLAB <-> ADAMS/Car) will be ready by end of this year. • Further investigations on target conflict between vehicle handling and driving comfort will be done by using numerical DoE and optimization methods – on going work.8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 17
  18. 18. Thank you very much for your kind attention! Contact Address: Mr. Werner Reinalter MAGNA Steyr Fahrzeugtechnik Liebenauer Hauptstraße 317 werner.reinalter@magnasteyr.com www.magnasteyr.com8.11.2011 Reinalter, Angrosch Disclosure or duplication without consent is prohibited 18

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