Vibro-acoustic engineering challengesin (hybrid and) electric vehicles
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Agenda
Introduction
Interior noise
Receiver perspective
Source perspective
Noise transfer
Exterior noise
Conclusion
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Legislation and RegulationPushing engineering to the limit
Legislation tightening
Pollutants remain a major area of focusTaking into account particle number (PN) in EUMass of particle matter is divided by two in US
Particle emissions becoming an issue for bothDiesel and GDI engine
New regulations - with harmonized WLTP andReal Driving Emissions (RDE) will stress theoperating conditions with significantcontributions of high loads and speeds
For diesel engines, urea consumption willbecome a challenge, requesting optimization incontrol strategies
Driving cycles in engine map
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Wheego Electric Cars, Inc.VolkswagenVehicle Production GroupToyotaTeslaSuburuSolectriaSmartScionSaturnSaabRamQUANTUM-PROCONPorschePlymouthNissanMitsubishiMercuryMercedes-BenzMcLarenMazdaLincolnLexusLand RoverKiaJeepJaguarInfinitiHyundaiHUMMERHondaGMCGeneral Motors EVFordFisker AutomotiveFiatDodgeCoda AutomotiveChryslerChevroletCadillacBuickBMWBentley MotorsAudiAcura
Market Introduction New Powertrain ArchitecturesAlternative Fuel Vehicles & Hybrid Electrical Vehicles
Source US http://www.afdc.energy.gov/data/
Increase of model variants~ 200 model market introductions yearly
Increased complexityNeighbourhood Electric Vehicles (NEV)Battery Electric Vehicles (BEV)Extended-range EVs (E-REV)Plug-in Hybrid Electric Vehicles(PHEV)Alternative fuels
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Constant Pressure on Weight ReductionDriving Innovations in Vehicle Engineering
Pressure on weight reductionfuel economy of a vehicle is generallyconsidered to increase by 6-8 % forevery 10% reduction in body weight
Technical & architectural complexityIntroduction new materialsImpact battery weight & alternativepowertrainsBalancing vehicle performance vs.
Ford, DowAksa jointly to develop carbon fiber for high-volume automotive light-weighting applications
Carbon Core of next-gen BMW 7 Series helps reducekg
New Opel Astra up to 200 kg lighter than predecessor witha slimmer body and all-aluminum engines.
GM applies Gen 3 advanced high-strength steel in newvehicle for China; 1,200 MPa Q&P steel
Continental Structural Plastics and Mitsubishi Rayonexploring joint venture for carbon fiber automotivestructural components
http://www.greencarcongress.com/
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Implications
Continued focus on fuel economy & emissions NVH & driving pleasure impacted by fuel economy
Multitude of options to be evaluated New Materials new engineering challenges
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Implications
Continued focus on fuel economy & emissions NVH & driving pleasure impacted by fuel economy
Multitude of options to be evaluated New Materials new engineering challenges
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Reducing CO2, at the price of NVH?D
river
sfo
rnew
vehi
cle
deve
lopm
ent
Emis
sion
&Fu
elEc
onom
y
Lightweightvehicles
Newpowertrain
and drivelineconcepts
Downsized ICE / Hybrid modeHigher torque irregularitiesDriveline integration issues
EV-mode operationNo low frequency ICE maskingLow and high frequency issues
Multi-Attribute BalancingBody Weight vs Body Stiffness
Increased Road Noise
Booming, clunk, rattleNon-speed related
Electric Motor Noise
Static StiffnessHandling
Ride comfortNVH
HVAC & Ancillary Noise
Tip-In/Out, Key-On/OffMode switch
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Reducing CO2, at the price of NVH?D
river
sfo
rnew
vehi
cle
deve
lopm
ent
Emis
sion
&Fu
elEc
onom
y
Lightweightvehicles
Newpowertrain
and drivelineconcepts
Downsized ICE / Hybrid modeHigher torque irregularitiesDriveline integration issues
EV-mode operationNo low frequency ICE maskingLow and high frequency issues
Multi-Attribute BalancingBody Weight vs Body Stiffness
Increased Road Noise
Booming, clunk, rattleNon-speed related
Electric Motor Noise
Static StiffnessHandling
Ride comfortNVH
HVAC & Ancillary Noise
Tip-In/Out, Key-On/OffMode switch
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ICE versus EV
Electric driven
Motor orderResonance
2600.000.00 Hzmic (CH1)
3500.00
900.00
80.00
-20.00
AutoPower mic (A) WF 126 [981.36-3466.8 rpm]
Motor order
ICE driven
Resonance
Off-zero harmonics. Origin?
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Hybrid - Electrical VehicleFrequency ranges of interest
Ancill. Noise EM/TM
Wind Noise
Inverter
[Km/h]
[Hz]200 1000 8000
[Km/h]
[Hz]200
Engine Structure B.
1000 8000
Road Noise Tire Noise
Wind Noise
2000
Road Noise Tire Noise
Engine Air B.
60
100
40
100
2000
400
400
ICE
EV
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Webinar agenda
Introduction
Interior noise
Receiver perspective
Source perspective
Noise transfer
Exterior noise
Conclusion
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Interior noiseThe Source Transfer Receiver model
20.00
80.00
X =Source (Fi,Qj) Transfer (NTF) Receiver (yk)
Assessing customer value(annoyance, quality, message)Setting targetsDesign engineering towards the righttargetsRelevant validation of targets
System modeling and engineeringNoise transfer mechanismsTPA, Modal Analysis, FEM/BEM
Materials, architectures, systemdesign engineering
Structural and acoustic lLoadIdentificationNoise source mechanismsSource modeling and engineeringSystem concepts and layoutengineering
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Interior noiseHEV Perception
EV: Low overall noise levelsNo low-order ICE noiseReduced masking of wind and tire noise=> cruising noiseReduced masking of noise from ancillaries=> idle and low-speed noise
New NVH typesTonal, high frequency noise of complexharmonic natureBroadband high-frequency noise not linked tooperating conditionHybrid mode switching=> Transient phenomenaLess dependency of the interior noise on the load=> less dynamic
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Interior noiseHEV Perception
New demands for describing sounds and settingtargets
Loudness: accounting for high-frequency effects(<> dBASharpness: shift of noises to higher frequenciesTonality, Tone-to-Modulation effects other than roughness
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Pursuing seemingly contradictory objectives
WorldAutoSteelReducing body structure weight by 35 percent and achieve NVH targets
Enhanced NVH performanceHelped achieve a 35 percentreduction in body structure weightEnabled engineers to identify andanalyze specific NVH problem areas
LMS Engineering services carried out the NVH simulation studies on the FSVproject in close collaboration with the consortium performing the crash andrigidity studies.
Use LMS Engineering capabilities to balance multiple performance attributes in parallelUse LMS Virtual.Lab early in concept design
Clever body design that balances low massand acceptable NVH performance
A comparison of EV- and ICE-powered classA/B car concept to enable target setting
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1.5 3
Interior noiseHEV Receiver Considerations
ICE EV
Case: WorldAutoSteel FSV concept studyBenchmark Small Vehicle ICE (3-cyl.) vs. EV PWT
Acceleration WOT
Case: WorldAutoSteel FSV concept studyBenchmark Vehicle EV PWT Acceleration WOT
Low Frequency (< 200 Hz): Low orders up to np/2
Mid Frequency (200 1000 Hz): Order np quietrange
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Interior noiseHEV Receiver Considerations
100 10000Hz3450
Articulation Index: 56% 73%
Order 4xnp10 dB
Case: WorldAutoSteel FSV concept studyBenchmark Vehicle ICE vs. EV PWT Constant speed 120kph, drivers ear
LF: road noise
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Interior noiseHEV Receiver Considerations
Articulation Index ICE 56%EV 73%
Prominence RatioEV order 4 np9.27 dB> 9 dB threshold
Tone to Noise RatioEV order 4 np11.03 dB> 8 dB threshold
Prominence ratio and tone-to-tone ratioare suitable for target setting
Case: WorldAutoSteel FSV concept studyBenchmark Vehicle EV PWT Acceleration WOT
Sound Indicators for EV Noise
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Interior noiseThe Source Transfer Receiver model
20.00
80.00
X =Source (Fi,Qj) Transfer (NTF) Receiver (yk)
Assessing customer value(annoyance, quality, message)Setting targetsDesign engineering towards the righttargetsRelevant validation of targets
System modeling and engineeringNoise transfer mechanismsTPA, Modal Analysis, FEM/BEM
Materials, architectures, systemdesign engineering
Structural and acoustic LoadIdentificationNoise source mechanismsSource modeling and engineeringSystem concepts and layoutengineering
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Interior noiseHEV Source Considerations
New noise sourcesElectric powertrain components
Electric MotorInvertorCurrent-control strategy
New secondary sourcesBattery coolingComplex gears in HEV
Greg Goetchius opinion in Sound &Vibration, April 2011
15
30
40
1510 Electric motor/gearbox
noiseWind noise
Road noise
Ancillary system noise
Other noise andvibration phenomenon
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Interior noiseHEV Source Considerations
Permanent Magnet MotorsMagnets embedded in the steelrotor
Induction MotorsCylinder of steel with aluminum orcopper conductors
Switched Reluctance MotorSoft magnetic steel material
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Interior noiseHEV Source Considerations
Noise produced by the Electromechanical Control System
Motor voltageand current(harmonics) Internal
forces
ElectromotorPCU VibrationsMotorcables
PWM Switching FrequencyVoltage/Current control- Sinusoidal- Space vector- Hysteresis
Permanent Magnet DCPM SynchronousInduction MotorsSwitched Reluctance
Current and voltageharmonics
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Interior noiseHEV Source Considerations
10000.000.00 Hzcurrent1 (CH105)
10000.00
400.00
20.00
-90.00
PSD current1 WF 381 [425.76-9947.7 rpm]
10000.000.00 HzMntl:1_06:+Z (CH3)
10000.00
400.00
20.00
-80.00
PSD Mntl:1_06:+Z WF 381 [425.76-9947.7 rpm]
10000.000.00 HzM1 (CH233)
10000.00
400.00
100.00
0.00
PSD M1 WF 381 [425.76-9947.7 rpm]
Phase current
Sound
Acceleration
SRM Spectrum of current, acceleration and sound - ODS
10000Frequency (Hz)
1330 Hz: 6330 Hz:Both square and ovalation modes are excited!
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Interior noiseHEV Source Considerations
Noise produced by the Electromechanical Control System: PWM ControlIM-drive: Increasing the switching frequency -> lower vibration speeds
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New motors generation for automotive propulsion
Punch PowertrainUsing LMS Engineering services and tools to cut development time by a factor of 2
Reduced total development time byat least 50 percentDeveloped new generation ofmotors with better NVHperformanceImplemented a new simulation-based process with knowledgetransfer
Virtual.Lab, we are now working on a new generation of commercially competitiveswitched reluctance motors for automotive propulsion
Diederik Brems, Mechanical Engineer
Couple the vibro-acoustic model with the electromagnetic modelCombine test and simulation for the creation of validated simulation models
Developing a powerful partnershipSwitched reluctance motors challenge NVHperformance
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Introduction
Interior noise
Receiver perspective
Source perspective
Noise transfer
Exterior noise
Conclusion
Webinar agenda
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Page 28 Siemens PLM Software
Interior noiseThe Source Transfer Receiver model
20.00
80.00
X =Source (Fi,Qj) Transfer (NTF) Receiver (yk)
Assessing customer value(annoyance, quality, message)Setting targetsDesign engineering towards the righttargetsRelevant validation of targets
System modeling and engineeringNoise transfer mechanismsTPA, Modal Analysis, FEM/BEM
Materials, architectures, systemdesign engineering
Structural and acoustic LoadIdentificationNoise source mechanismsSource modeling and engineeringSystem concepts and layoutengineering
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Interior noiseHEV Transfer System Engineering
Experimental approach: Transfer Path AnalysisEnergetic methods: higher frequenciesTime domain TPA: Transients & AuralizationTPA for exterior acoustics
Numerical approachFull audible frequency rangeFast Multi-pole BEMHybrid approach: HF method (Ray Tracing)+ LF techniques (FEM-BEM)
Fastmultipole
BEM
invertor
chargermotor
batteries
Airborne
Structure borne
TPA
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Interior noiseHEV Transfer System Engineering
Can weakening NTF target gain weight?
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Interior noiseHEV Transfer System Engineering
EV less low-frequency noise=> gain mass in structural design by reducing steelsheet thickness and using of vibration damping steel
EV high-frequency tonal components=> increased HF isolation and absorption=> specific sound pack design
Body weight target=> 35% mass reduction=> 190 kg body structure
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BYD Auto Company LimitedBoosting NVH performance of plug-in hybrid vehicle fleet
Improving the NVH development and control process
Reduced noise and vibration levelsin hybrid vehicles and other NVH-related problems, such as wind andcooling pump noise
Optimized overall hybrid vehiclestructure for NVH performancewithout compromising other qualityparameters, such as drivability andhandling
15 versions of the Qin were praised for NVH performance by our customers.Working together with LMS Engineering for NVH optimization has helped usposition ourselves as the top seller in plug-in new energy
Zhang Rongrong, Manager NVH performance research division
Dedicated and comprehensive troubleshooting methodologyIntegrated simulation and testing to determine and resolve the root causes of problems
Target setting and benchmarking NVH optimization
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Webinar agenda
Introduction
Interior noise
Receiver perspective
Source perspective
Noise transfer
Exterior noise
Conclusion
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Page 34 Siemens PLM Software
eVADER Exterior sound of EV (EU Project)System engineering approach - Sound Synthesis and Propagation
Speaker Directivity Sound Reflection and Propagation
Multiple speakers in bumperCombined with sound environmentAnd Beam-forming (phase shift)
=> Directional warning sound field
EC Project eVADER - SCP1-GA-2011-285095Electric Vehicle Alert for Detection and Emergency Response
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Introduction
Interior noise
Receiver perspective
Source perspective
Noise transfer
Exterior noise
Conclusion
Webinar agenda
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Page 36 Siemens PLM Software
Conclusion: EV and HEV have a specific NVH behavior
Source-Transfer-Receiver approachSources: Motor/invertor, gear, specific appliancesand support systemsReceiver: Absence of masking, tonal componentsof complex nature, warning soundsTransfer: High-frequencies predominant,lightweight design
Revisit engineering methods and toolsSignal capturingSignal analysisSound quality indicesExperimental system modeling (TPA) extension toHF & auralizationNumerical system modeling extension to HFActive sound generation more prominent
New research and skills challenges emergeMulti- & interdisciplinary
-Systems approach is requiredFrom architecture evaluation to system integrationand validation
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Simcenter solutions for Automotive NVH & Acoustics
Legislation and regulation
New powertrain concepts
Lightweight structures
Increase vehicle performance
www.siemens.plm/simcenterRealize innovation.Unrestricted © Siemens AG 2017