Sreekanth R, Rangarajan S, Anand G -System Simulation

Passenger Car baseline Fuel Economy Validation with Test data on IDC & FE Improvement Strategies Prediction to improve CAFE Ratings Sreekanth R, Rangarajan S, Anand G -System Simulation PWT CAE System Simulation GT-SUITE User Conference Jan 15, 2018

Outcome CONTENTS of the Seminar 1. Modelling & Validation of FE on Indian Driving Cycle in GT-SUITE. 2. Modelling FE improvement ideas using GT-SUITE as POC. Component level FE ideas ECU control logic FE ideas Summary, Conclusions and FE Challenges for Automotive Industry FE Baseline validation on Indian Driving Cycle(IDC) 1. Driveline optimization 2.Drag Coefficient & LOW RRC Tires 1. Stop-Start 2. Power-Eco mode Future Scope 2

Contents Introduction Baseline Fuel Economy validation on IDC FE improvement ideas Summary & Conclusions Challenges & Future scope 3

1- INTRODUCTION Background- FE Challenges How to balance them..?? 4

1- INTRODUCTION Challenges and Motivation Vehicle FE improvement concept freeze Vehicle performance evaluation Modeling using simulation tools in upstream development stages (Limited/no test data) Prototyping & final test Challenges in Real World Testing Benefits with 1D GT-SUITE Simulation Prototype Cost involved Vehicle test facility Complexity. No Prototype Less Cost Less efforts Good accuracy with Repeatability detailed physics of system to be modeled!! 5

1- INTRODUCTION 1D GT-SUITE vehicle model Physical Layout-Chassis Dyno Simulation Layout in GT-SUITE Deliverables FE Validation Vehicle Modelling FE Validation on IDC FE Improvement Transmission Optimization Drag Coefficient & Low RRC Tires Start-Stop Power-Eco Modes 6

POC validation Compoent Level improvement System Level Component Level 1- INTRODUCTION Simulation Steps Modeling & System Integration Drive model Engine, ECU (Simple / Detailed FRM), Fuel Cut off logic. Transmission, TCU Carbody Component Drive model: Speed target PID. Engine: Map based model with Engine BSFC map. Transmission: 6 speed MT gear box & FDR. Driving Cycle Fuel Economy simulation on IDC System Level IDC (Indian Driving Cycle) Vehicle speed & gear position target as time profile. FE improvement Component level improvement ECU logic improvement Control Logic Drag coefficient and Tire rolling resistance target data. Stop-Start logic and Power-Eco mode accelerator pedal map scaling. Driving Cycle IDC Real World Driving Cycle/ Customer driving cycle Validation FE validation of baseline Validation of Stop-Start and Power Eco mode POC with real world FE improvement data from OEMs(Open claims/resources) 7

Engine speed(rpm) Vehicle speed(kmph) 2- Baseline FE validation on IDC Baseline FE validation on IDC IDC Cycle data: Indian Driving Cycle(IDC Cycle) 100 6 80 5 4 60 3 40 2 20 1 0 0 0 200 400 600 800 1000 1200 Time(sec) Vehicle Speed(Kmph) Gear(-) Gear(-) Engine speed: 3500 Engine speed_idc Cycle 0 200 400 600 800 1000 1200 Time(sec) Baseline configuration 8

Fuel Economy(Kmpl) Fuel Consumption(grams) 2- Baseline FE validation on IDC Baseline FE validation on IDC Baseline model Fuel Consumption-Simulation: 700 Baseline cumulative fuel consumption Baseline 0 200 400 600 800 1000 1200 Time(sec) 23 Baseline FE Validation: Test(Chassis Dyno) Simulation -2.4% 15 9

Engine speed(rpm) 3- FE improvement POC 1 Driveline optimization Driveline optimization: Driveline inputs in GT-SUITE: Engine speed comparison: 3500 Engine speed comparison 20 0 0 200 400 600 800 1000 1200 Time(sec) 0 6000 30 Baseline configuration Optimized configuration 10

Fuel Economy(Kmpl) Fuel Consumption(grams) 3- FE improvement POC 1 Driveline optimization Fuel Consumption comparison: 700 Cumulative Fuel Flow Baseline Driveline Optimization 0 Time (s) 1200 23 FE improvement: Base line simulation Driveline optimization +3 % 15 11

3- FE improvement POC 2 Air drag reduction Factors impacting Air drag: Drag inputs in GT-SUITE: Note: CAR model only for representation 12

Fuel Economy(Kmpl) Fuel Consumption(grams) 3- FE improvement POC 2 Air drag reduction Fuel Consumption comparison: 700 Cumulative Fuel Flow Baseline Aerodynamic drag reduction 0 1200 Time (s) 23 23 FE improvement: Base line simulation Air drag reduction +3 % 15 15 13

3- FE improvement POC 3 Low RRC Tires + Tire pressure up Factors impacting Tire rolling resistance: construction Tire model inputs in GT-SUITE: Pattern Tire Pressure Tire Size 14

Fuel Economy(Kmpl) Fuel Consumption(grams) 3- FE improvement POC 3 Low RRC Tires Fuel Consumption comparison: 700 Cumulative Fuel Flow Baseline Low RRC Tires 0 200 400 600 800 1000 1200 Time(sec) 23 FE improvement: Base line simulation Low RRC tires + Tire pressure Up +7 % 15 15

4- FE improvement POC 4 Stop-Start System Start-Stop control modelled in GT-SUITE: Vehicle speed= 0 Kmph & Engine speed = Idle speed & Driver accelerator demand = 0 % & Coolant temperature > ex: 35 deg.c Traffic condition Stop-Start in GT-SUITE: Engine Stop-Start Selection Stop-Start Control in GT-SUITE 16

Fuel Economy(Kmpl) Fuel Consumption(grams) 4- FE improvement POC 4 Stop-Start System Fuel Consumption comparison: 700 Cumulative Fuel Flow Baseline Start-Stop System 0 200 400 600 800 1000 1200 Time(sec) 23 FE improvement: Base line simulation Stop-Start +6.7 % 15 17

4- FE improvement POC 5 Power-Eco Mode: POWER-ECO Mode modelled in GT-SUITE: facilitates driver to select between the 2 modes Power and ECO. ECO mode provides better fuel economy by limiting the maximum Torque cure. Pedal Map in GT-SUITE: Simulation Carried on Real World Driving cycle Note: While using RWDC with ECO-Mode, the zones with high vehicle acceleration are not followed by simulation vehicle due to low max. torque in ECO mode. 18

Fuel Economy(Kmpl) 4- FE improvement POC 5 Power-Eco Mode: Fuel Consumption comparison on Real World Driving Cycle: 20 0 0 6000 30 23 FE improvement: Base line simulation Eco mode +6.3 % 15 19

5- Summary FE Summary & Conclusions for IDC & Real World Drive Cycle FE improvement varies based on Drive Cycle Conditions. Technologies to gain FE without compromise in cabin comfort are in development START-STOP IDC cycle Driver aggressiveness monitoring systems are being implemented W.r.to Base +7% W.r.to Base +3% +6% ECO MODE +6% Real World Cycle W.r.to Base Low drag vehicle designs are being developed Ex: eliminating ORVMs, Plasma aerodynamics IDC cycle W.r.to Base +7% +3% W.r.to Base IDC cycle DRIVELINE OPTIMIZATION AERO-KIT +3% IDC cycle AT, CVT, DCT Drivelines Base LOW RRC TIRES + Tire pressure up Low weight tires, Advanced material are the future 20

5- Summary Challenges in FE improvement ideas Poor Stability & more braking distance Eco modes & Engine start/stop Eco mode: Lower performance feel. Engine start/stop Engine start/stop: Impact on starter motor life. Passenger s discomfortness due HVAC cut off. Reduced traction effect (Braking distance/skidding)during rain or wet climatic condition. Poor Stability/rattling noise in High speeds. Lower Rolling resistance Aero dynamic drag Air flow Reducing air drag will affect the air flow in frontal area and leads to lesser cooling efficiency in Radiator and intercooler etc. Reducing the height and width of the car will reduce the frontal area which will reduce the drag force. But which will make uncomforatability of passengers seating. 21

5- Summary Future scope Integration of lubrication, ETM, HVAC and Vehicle cooling Advanced engine technologies & Co-Simulation Hybrid powertrain configurations Efficient thermal and waste heat management Energy synthesis and optimization 22

Acknowledgments Dan Marsh, P.Dimitrakopoulos & Jonathan Zeman - Gamma Technologies, USA. Amit Patankar & Sandeep Jain ESI Group, India. Vinayaga Moorthy DGM, Powertrain CAE, RNTBCI, Chennai, India. 23

Thank You 24