Group Meeting Presentation

1
Group Meeting Presentation

• Research Update

2
Targets

• Decide which software to use for vehicle
  simulations.
• Validate results.

3
Targets

• Desired final Output from Vehicle Simulations
• TTW efficiency of the vehicle over a driving
  cycle.
• TTW CO2 emissions over a driving cycle.
• Consumer-Related Attributes
• Range
• Drivability
• All these should be done for a number of
  different future vehicle and powertrain
  technology configurations.

4
What is a Driving Cycle?

• Standardized Driving Schedule to test fuel
  consumption and/or emissions from a vehicle.
• This is where official mpg figures come from
• Standardized for different countries and driving
  conditions (urban/highway)
• Parameters Specified
• Vehicle Velocity as a function of time.
• Gear selected as a Function of time-Sometimes

5
Driving Cycle
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Alternative Software Presentation

• ADVISOR
• Developed by the NREL and AVL
• Pros
• Extremely Detailed Simulations(40input
  variables)
• Ability to do drivability tests
• Range
• Maximum Velocity
• Miss-trace velocity test
• 0-60mph acceleration
• 40-60mph (passing) acceleration
• Gradeability (long hill climbing) test

7
Alternative Software Presentation

• ADVISOR
• Cons
• Detailed Simulations Require Detailed input
• Many input variables
• Variables are rarely constant-usually variable
  maps (e.g. engine ? function of T and rpm,
  gearbox ? function of T, rpm, gear)
• Could be a problem for future vehicle simulations
  

8
Alternative Software Presentation

• QSS
• Developed by the ETH
• Pros
• Easy to use 10 input variables
• Additional value for simplicity when future
  vehicle calculations are required
• Will do TTW calculations(CO2,mpg)
• Cons
• Very limited ability to do drivability tests
• Range-YES
• Maximum Velocity-YES
• Miss-trace velocity test-NO
• 0-60mph acceleration-NO
• 40-60mph (passing) acceleration-NO
• Gradeability (long hill climbing) test-Difficult

9
Validation Tests

• QSS vs QSS
• (OTR 2020,Comparative Assessment of Fuel Cell
  Cars)
• QSS vs ADVISOR
• QSS ADVISOR vs reality
• For each powertrain technology to be simulated
• ICE cars
• ICE alternative Fuels
• ICE hybrids
• FC hybrids
• BEV

10
Validation Tests

• QSS vs QSS
• Parameters to be fixed
• Vehicle
• Masses-Rotating Inertias (overall)
• Aerodynamics (cd,A)
• Transmission
• Gear ratios-Final Drive Ratios
• Transmission ? (constant)

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Validation Tests

• QSS vs QSS
• Parameters to be fixed
• Engine
• Efficiency

12
Validation Tests

• Assuming constant fmep,ni
• We end up with

13
Validation Tests

• QSS vs QSS
• Parameters to be fixed
• Engine
• Peak Torque Curvef(rpm)

14
Validation Tests

• QSS vs QSS
• One parameter is enough

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Validation Tests

• QSS vs ADVISOR
• Parameters to be matched
• Vehicle-easy apart from the rotating inertias
  part-DONE
• ENGINE
• Map-Fixed
• Max Torque-Fixed
• Braking TorqueF(?)-Not changed
• Results 17 difference on the USO6(6.1l/100km
  ADVISOR-5.18l/100km QSS)

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Real Engine Map
17
QSS-Engine Map
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Validation Tests

• QSS vs ADVISOR
• Parameters to be matched
• Transmissions
• Primary and final drive ratios-MATCHED
• Efficiency ?f(?,?,i) vs constant-Still not done
• Results 13 difference on the USO6(5.9l/100km
  ADVISOR-5.18l/100km QSS)

19
Validation Tests

• QSS vs ADVISOR
• Parameters to be matched
• Control logic
• Idling-fixed
• Gear shifting strategy-still not fixed

20
Future Work

• Future Work
• Getting the difference below 10 over different
  cycles
• Checking degree of accuracy vs reality
• Choosing program
• Choosing Assumptionsgt
• Getting to the real simulations