lap time simulation crucial for racecar concept evaluation€¦ · guinness world record in formula...

Fabrice Oehler AMZ Racing, Christoph Hahn MathWorks

Lap Time Simulation – Crucial for Racecar

Concept Evaluation

WR Film

Guinness World Record in Formula Student

AMZ Racing set a new world record for the fastest 0-100 km/h

acceleration of an electric car in 2014

5/10/2016 Akademischer Motorsportverein Zürich | Fabrice Oehler 3

1.785 s

Guinness World Record in Formula Student

AMZ Racing set a new world record for the fastest 0-100 km/h

acceleration of an electric car in 2014

Greenteam Stuttgart set a new record in summer 2015

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1.785 s

1.779 s

Formula Student

About Formula Student

Largest engineering

competition worldwide

Over 500 Teams with

10’000 members

Combustion and electric

class

Different static and

dynamic events

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Points in a Formula Student Event

Engineering Design

Business Plan

Cost Event

Acceleration

Skidpad

Autocross

Endurance

Efficiency

AMZ Racing

AMZ Racing

Builds race cars for Formula Student since 2007

Since 2010 six electric cars were built

Since 2013 first place in Formula Student Electric world ranking

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Season 2015 - flüela

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4 wheel hub motors

25.7 Nm, 37 kW, 3.25 kg

Lithium Polymer accumulator

6.46 kWh

Full Aerodynamics-Package

Drag Reduction System (DRS)

Adaptive Damping System

Simulink programmed Vehicle Control Unit

2nd place in Formula Student Germany, 1st places in Austria and Spain

Lap Time Simulation

Motivation to Use Lap Time Simulation

Only eight months for design and manufacturing a race car

We need a tool for decision making

Different concept decisions can be analyzed

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Accumulator Capacity Gearbox Transmission Ratio Aerodynamic Sensitivities

Workflow

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Concept idea Simulation

Evaluation

Workflow

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Visualize

Car parameters

𝐿

ℎ

𝑚

Simulate Calculate and analyze Event

𝑥

𝑦

Velocity difference

Structure of the Simulation Model

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Control

systemsDriver

Powertrain

/ Tires

Two-track

model

Structure of the Simulation Model

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Control

systemsDriver

Powertrain

/ Tires

Two-track

model

Software Demonstration

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Results

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Velocity difference of a 4WD car vs. a 2WD car

Δ𝑣[𝑘𝑚/ℎ]

32

28

24

20

16

12

8

4

0

0

100

200

300

400

500

600

700

Po

ints

FSG Acceleration Points

Skidpad Points

Autocross Points

Endurance Points Total

2WD, no Aero 2WD, Aero 2WD, DRS 4WD, no Aero 4WD, Aero 4WD, DRS

Results – Concept Simulation

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Results – Energy Simulations 4WD with DRS

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0

100

200

300

400

500

600

700

5,5 5,7 5,9 6,1 6,3 6,5 6,7 6,9 7,1

Po

ints

FSG

Battery Capacity [kWh]

Acceleration Points

Skidpad Points

Autocross Points

Endurance Points Total

625

630

635

640

645

650

5,5 5,7 5,9 6,1 6,3 6,5 6,7 6,9 7,1

Po

ints

FSG

Battery Capacity [kWh]

Validation

Different tests were made to validate our results:

Weight sensitivity validation

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Laptime deviation

Lapsim On-track test Delta

+ 1 kg + 0.087 % + 0.082 % 6 %

+ 10 kg + 0.893 % + 0.821 % 8 %

Validation

Different tests were made to validate our results:

Weight sensitivity validation

Aerodynamics sensitivity validation

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Laptime deviation Aero vs. no Aero

Lapsim On-track test Delta

3.82 % 3.97 % 4 %

Conclusions

By using Lap Time Simulation we get a decision-making basis for

different concepts

Aerodynamic setups

Amount of accumulator capacity

Transmission ratio

Models are simplifications, but they are very helpful.

Currently implementing suspension system.

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MathWorks Support for Formula Student

Complimentary Software

MATLAB and Simulink

Racing Lounge

Online Training for

Physical Modeling

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Thanks for Your Attention