Aachen Colloquium China 2011 Determination of the Functional Performance of a Series Electric Vehicle Beijing, November 1 st - 2 nd, 2011 Lutz Eckstein Roland Wohlecker René Göbbels Forschungsgesellschaft Kraftfahrwesen mbh Aachen Slide Nr. 1
Agenda Introduction Market Overview Electric Vehicles Functional Benchmarking of the Mitsubishi i-miev Design Benchmarking of the Mitsubishi i-miev Summary Slide Nr. 2
Introduction About fka (1/2) Basic data: Founded in 1981 as a spin-off from the Institut für Kraftfahrzeuge of RWTH Aachen University (ika) Together with co-operation partner ika access to a total staff of approx. 300 employees Project structure: 55 % advanced engineering 20 % serial vehicle development 25 % future development and others References: Automotive customers from Europe, USA und Asia 27 % OEM 72 % suppliers 1 % public funded research Slide Nr. 3
Introduction About fka (2/2) Research & development topics in the departments Chassis Body Drivetrain Electronics Acoustics ADAS Consulting with the development portfolio: > Benchmarking > Construction > Conceptual design > Prototyping > Simulation > Testing Slide Nr. 4
Introduction Motivation for Benchmarking of Electric Vehicles High number of variating concepts and development status of electric vehicles Knowledge of the actual state of the art and analysis of current solutions for the future development of electric vehicles is very important Functional and design benchmarking (analysis of functional properties and of the architecture) as a basis for the determination of the state of the art Benchmarking at the fka Methodical and technical know-how existent by numerous bilateral benchmarking projects and the existing overall vehicle expertise The next benchmarking analysis of an electric vehicle is currently in discussion with potential clients Slide Nr. 5
Agenda Introduction Market Overview Electric Vehicles Functional Benchmarking of the Mitsubishi i-miev Design Benchmarking of the Mitsubishi i-miev Summary Slide Nr. 6
Market Overview Electric Vehicles Vehicle Categories and Classes (1/2) Vehicle categories Concept Vehicle classes Sport Off-Road MPV Prototype Luxury Upper Medium Medium Series production Lower Medium Small Mini (4 wheels) Mini (3 wheels) Slide Nr. 7
Market Overview Electric Vehicles Vehicle Categories and Classes (2/2) l Vehicle categories 7 Mini (3 wheels) 2 Concepts Mini (4 wheels) Mini (3 wheels) Mini (4 wheels) Small 6 13 Concepts Prototypes Sport 7 Series production 13 Prototypes 27 Series production 7 Sport Concepts 16Prototypes Small 10 Series production 6 n = 148 Overall number of vehicles Vehicle class Overall distribution number of vehicles 4 1 Concepts 6 6 Prototypes 6 17 17 Slide Nr. 8 26 26 Series production Concepts Key Prototypes learnings: 9 9 148 Electric vehicles 32 32 47 47 Mini (3 wheels) Mini (3 wheels) Mini (4 wheels) Mini (4 wheels) Small Small Lower Medium Lower Medium Medium Medium Upper Medium Upper Medium Luxury Luxury MPV MPV Off-Road Off-Road Sport Sport Series 77 % production of all electric vehicles can be assigned to the vehicle classes Mini (3 wheels/4 wheels), Small and Sport For the analysis of the functional properties of electric vehicles, a series production vehicle of the classes Mini or Small is suitable
Market Overview Electric Vehicles Vehicle Classes Mini and Small Overview electric series production vehicles Mini (3 wheels) Mini (4 wheels) Smiles AG CityEL (V1) Corbin Sparrow Aixam Mega AEV Kurrent Small Mitsubishi i-miev Hyundai i10 Honda EV Plus Fiat Panda Elektra Key learnings: The 3 wheels and 4 wheels electric vehicles of the vehicle class Mini are not comparable (regarding the aspects comfort and driving dynamics) with conventional cars and thus not adequate for the analysis of functional properties of electric vehicles The Mitsubishi i-miev as one of the first real series electric vehicles with a comparable performance to conventional cars builds the basis for the benchmarking analysis Slide Nr. 9
Agenda Introduction Market Overview Electric Vehicles Functional Benchmarking of the Mitsubishi i-miev Design Benchmarking of the Mitsubishi i-miev Summary Slide Nr. 10
Functional Benchmarking Mitsubishi i-miev Overview Functional benchmarking Design benchmarking Chassis Electric/ Electronics Acoustics Drivetrain Body Overall vehicle Inertia parameters k&cparameters Road tests Energetic main power supply Energy consumptions Interior and exterior noise measurement Accelerated passing Driving resistance Energy consumption (NEDC) Efficiency electric drive Characterisation of the battery Bending and torsion stiffness Modal analysis (1 st bending, 1 st torsion) Destructive benchmarking Non-destructive benchmarking Vehicle disassembly Component analysis: Weight Dimensions Fitting positions Joining techniques Photo documentation Slide Nr. 11
Functional Benchmarking Mitsubishi i-miev Chassis (1/2) Determination of inertia parameters Measuring of the overall vehicle weight for a defined load condition Determination of the centre of gravity in x-, y- and z-direction Determination of the mass moment of inertia in x-, y- and z-direction In-house patented vehicle inertia measuring machine (VIMM) Centre of gravity x s [mm] 1199 y s [mm] 628 z s [mm] 559 Slide Nr. 12
Functional Benchmarking Mitsubishi i-miev Chassis (2/2) Comparison of the centre of gravity with a conventional vehicle Mitsubishi i-miev Volkswagen Polo V Vehicle dimensions x [mm] 3475 y [mm] 1475 z [mm] 1610 Centre of gravity x s [mm] 1199 y s [mm] 628 z s [mm] 559 Vehicle dimensions Source: Volkswagen AG x [mm] 3970 y [mm] 1682 z [mm] 1462 Centre of gravity x s [mm] ~ 1600 y s [mm] ~ 730 z s [mm] ~ 550 Key learnings: Nearly identical centre of gravity in z-direction in spite of higher z-dimensions of the Mitsubishi i-miev (cause of the battery position in the underbody sector) Slide Nr. 13
Functional Benchmarking Mitsubishi i-miev Acoustics (1/2) Accelerated passing Accelerated passing based on 70/157/EWG resp. ECE R51-3 Transmission of engine speed and vehicle velocity by telemetry In-house vehicle acoustic analysis on ika test track Maximum sound pressure level Max. sound pressure level left [db(a)] Max. sound pressure level right [db(a)] 68.03 68.26 Slide Nr. 14
Functional Benchmarking Mitsubishi i-miev Acoustics (2/2) Comparison of the maximum sound pressure level with a conventional vehicle Mitsubishi i-miev Volkswagen Polo V Maximum sound pressure level Max. sound pressure level left [db(a)] Max. sound pressure level right [db(a)] 68.03 68.26 Maximum sound pressure level Max. sound pressure level left [db(a)] 72.87 Max. sound pressure level right [db(a)] 72.44 Maximum sound pressure level Source: Mitsubishi Information manufacturer [db(a)] 66 Maximum sound pressure level Source: Volkswagen AG Information manufacturer (BM) [db(a)] 73 Key learnings: Mitsubishi i-miev with a lower maximum sound pressure level (68 db(a)) than the VW Polo (max. 73 db(a)) by identical testing procedures (70/157/EWG) Slide Nr. 15
Functional Benchmarking Mitsubishi i-miev Drivetrain Determination of the driving resistance Performance of coast load tests Identification of the driving resistance components (rolling resistance coefficient, aerodynamic resistance) In-house driving resistance analysis Driving resistance parameters c d -Value [-] 0.33 Cross sectional area A [m²] 2.14 Rolling resistance value f r [-] 0.011 Slide Nr. 16
Functional Benchmarking Mitsubishi i-miev Body (1/4) Analysis of global stiffnesses Use of a special test bench for the determination of the torsion and bending stiffness of the body-in-white (in combination with stiffness increasing body components) Determination of the body deflections by the use of 50 analogue measuring devices Determination of the bending and torsion stiffness characteristics Calculation of a value for the bending and torsion stiffness In-house body stiffness analysis test bench BIW (without battery) Torsion stiffness [Nm/ ] <10000 Lightweight quality [kg/(nm/ *m²)] 9.31 BIW (incl. battery) Torsion stiffness [Nm/ ] <10000 Lightweight quality [kg/(nm/ *m²)] 16.13 Slide Nr. 17
Functional Benchmarking Mitsubishi i-miev Body (2/4) Comparison of the global stiffnesses with a conventional vehicle Mitsubishi i-miev Volkswagen Polo V BIW (without battery) Torsion stiffness [Nm/ ] <10000 Lightweight quality [kg/(nm/ *m²)] 9.31 BIW Source: Volkswagen AG Torsion stiffness [Nm/ ] 18000 Lightweight quality [kg/(nm/ *m²)] 3.5 BIW (incl. battery) Torsion stiffness [Nm/ ] <10000 Lightweight quality [kg/(nm/ *m²)] 16.13 Weight BIW: 213 kg Weight BIW: 227 kg Key learnings: Nearly identical weight of the BIW of both cars VW Polo with a very high torsion stiffness in comparison to the Mitsubishi i-miev Slide Nr. 18
Functional Benchmarking Mitsubishi i-miev Body (3/4) Modal analysis Use of a special test bench for the determination of the 1 st torsion and the 1 st bending of the body-in-white 100 measuring points with tri-axial accelerometers Acquisition of the measuring data with a multi channel frontend Generation of a wire frame of the BIW Calculation of the 1 st torsion and the 1 st bending Graphic design of the different oscillations forms (1 st torsion and 1 st bending) BIW (without battery) 1 st Torsion [Hz] 34 1 st Bending [Hz] 57 Slide Nr. 19
Functional Benchmarking Mitsubishi i-miev Body (4/4) Comparison of the results of the modal analysis with a conventional vehicle Mitsubishi i-miev Volkswagen Polo V BIW (without battery) 1 st Torsion [Hz] 34 1 st Bending [Hz] 57 BIW Source: Volkswagen AG 1 st Torsion [Hz] 43 1 st Bending [Hz] 46 Weight BIW: 213 kg Weight BIW: 227 kg Source: Volkswagen AG Key learnings: Mitsubishi i-miev with a higher bending eigenfrequency VW Polo with a higher torsion eigenfrequency Slide Nr. 20
Agenda Introduction Market Overview Electric Vehicles Functional Benchmarking of the Mitsubishi i-miev Design Benchmarking of the Mitsubishi i-miev Summary Slide Nr. 21
Design Benchmarking Mitsubishi i-miev General Approach Operating cycle 1 Overall vehicle (base) 2 Naming single components 3 Listing single components 40000000 Electric/Electronic 41000000 High Voltage Components 41100000 Wiring Main Power Supply 41110000 High Voltage Battery 41110101 High Voltage Battery - AC/DC-Converter_1 41110102 High Voltage Battery - AC/DC-Converter_2 41110201 Charging Cable High Voltage Connection_1 41110202 Charging Cable High Voltage Connection_2 41120000 Electric Engine 41120101 AC/DC-Converter - Electric Engine_1 41120102 AC/DC-Converter - Electric Engine_2 41120103 AC/DC-Converter - Electric Engine_3 4 Vehicle disassembly 5 Analysis single components Code Component 22200000 Naming Gearbox Weight (incl. joining techniques) [kg] 19.3 Weight joining techniques [g] 237.8 Length [mm] 397 Width [mm] 300 Height [mm] 300 Joining Techniques Type Number Screw M10 3 Screw M12 1 Slide Nr. 22
Design Benchmarking Mitsubishi i-miev Weight Distribution Vehicle Areas (1/2) Overview vehicle areas Overall vehicle 4 Electronic 1 2 Body 10% 15% Drivetrain Weight distribution Mitsubishi i-miev 11% 10% 15% 29% 11% 35% 35% 29% Body Drivetrain Karosserie Antrieb Chassis Fahrwerk Electric/ Electronic Interior Elektronik Interieur Vehicle area Weight [kg] 5 Interior 3 Chassis Body 383 Drivetrain 322 Chassis 165 Electric/Electronic 109 Interior 119 Overall weight 1098 Slide Nr. 23
Design Benchmarking Mitsubishi i-miev Weight Distribution Vehicle Areas (2/2) Comparison of the weight distribution with a conventional vehicle Mitsubishi i-miev 13% Volkswagen Polo V 29% 35% 11% 10% 35% Vehicle curb weight: 1100 kg 15% 29% Body 6% Drivetrain Karosserie Antrieb Chassis 19% Electric/ Electronic Interior Fahrwerk Elektronik Interieur 27% 13% 35% 6% 35% Vehicle curb weight: ~1200 kg 19% 27% Body Drivetrain Body Chassis Drivetrain Chassis Electric/ Electronic Interior Electric/ Electronic Interior weights w/o driver Key learnings: Nearly the same weight distribution of the Mitsubishi i-miev and the VW Polo V in total Slide Nr. 24
PE CE HV-Wiring Design Benchmarking Mitsubishi i-miev Weight Distribution High Voltage Electronics Weight distribution HV electronics 8% 8% 2% 2% 2% 2% 0% 0% 26% 26% 17% 17% 23% 23% 22% 22% High Hochvoltbatterie voltage battery Electric Elektromotor engine DC/DC-converter/ charge Wandler/Ladegerät unit AC/DC-converter AC/DC-Wandler Heater Heizung Air conditioning Klimatisierung DC/DC-converter/ charge DC/DC- unit AC/DC-converter Wandler/Ladegerät AC/DC-Wandler 0% 2% 1% 0% 2% 1% 0% 0% 41310100 41310200 7% 7% 41310300 41310400 8% 8% 35% 41310501 41310502 5% 35% 41310501 41310502 5% 41310600 41310700 41310600 41310700 16% 16% 41310800 41310900 41310800 41310900 6% 41311000 41311100 12% 6% 5% 41311000 41311100 12% 5% 2% 41311200 41311300 1% 2% 41311200 41311300 1% Analysis DC/DC-converter/charge unit Code Naming 41310100 Housing DC/DC-converter/charge unit 41310200 Cap housing charge unit 41310300 Cover line filter charge unit 41310400 Line filter charge unit 41310501 Control board charge unit 1 41310502 Control board charge unit 2 41310600 Transformer-/spool unit charge unit 41310700 Cap housing DC/DC-converter 41310800 Control board DC/DC-converter 41310900 Cooling plate 41311000 Support sheet control board DC/DC-converter 41311100 Data cable DC/DC-converter 41311200 Ground cable DC/DC-converter 41311300 Cable cover DC/DC-converter Slide Nr. 25
Design Benchmarking Mitsubishi i-miev Detailed Component Analysis 41310100 - Housing DC/DC-converter/ charge unit 41310800 - Control board DC/DC-converter Code Component 41310100 Naming Housing DC/DC-converter/charge unit Weight (incl. JT) [kg] 3.99 Weight JT [g] 50.1 Length [mm] 395 Width [mm] 285 Height [mm] 146 Joining Techniques Type Screw M8 Number 3 Code Component 41310800 Naming Control board DC/DC-converter Weight (incl. JT) [kg] 0.85 Weight JT [g] 25.6 Length [mm] 255 Width [mm] 200 Height [mm] 36 Joining Techniques Type Screw M4 Number 16 Slide Nr. 26
Agenda Introduction Market Overview Electric Vehicles Functional Benchmarking of the Mitsubishi i-miev Design Benchmarking of the Mitsubishi i-miev Summary Slide Nr. 27
Summary Testing results Mitsubishi i-miev Length [mm] 3475 Width [mm] 1475 Height [mm] 1610 Curb weight [kg] 1100 Payload [kg] 275 Track width front [mm] 1310 Track width rear [mm] 1270 Torsion stiffness BIW [Nm/ ] <10000 Lightweight quality [kg/(nm/ *m²)] 9.31 Torsion eigenfrequency [Hz] 34 Bending eigenfrequency [Hz] 57 C d -value [-] 0.33 Cross sectional area [m²] 2.14 Rolling resistance value f r [-] 0.011 Max. sound pressure level [db(a)] 68 CoG (x S ) [mm] 1199 CoG (y S ) [mm] 628 CoG (z S ) [mm] 559 Slide Nr. 28
Summary In January 2011, the fka started a continuous design and functional benchmarking for electric vehicles Analysis of the vehicle areas body, drivetrain, chassis, electric/electronics and acoustics on in-house test benches Choice of the Mitsubishi i-miev as one of the first real series electric vehicles (regarding the aspects driving dynamic and comfort comparable to conventional cars) Good performance regarding the aspects maximum sound pressure level and CoG-position, sufficient performance regarding the torsion/bending stiffness and the modal analysis of the body Carbon dioxide emissions comparable to a efficient conventional vehicle of same size The Mitsubishi i-miev is a well performing electric vehicle with good driving characteristics (like typical small series vehicles) Full benchmarking results are available per online-database for consortium partners (small using fee per year) Continuation of the benchmarking activities with the Nissan Leaf in January 2012 Slide Nr. 29
Thank you for your attention! Slide Nr. 30