Lap Time Simulation Crucial for Racecar Concept Evaluation Fabrice Oehler AMZ Racing, Christoph Hahn MathWorks
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 1.785 s 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 3
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 1.785 s Greenteam Stuttgart set a new record in summer 2015 1.779 s 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 4
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 Points in a Formula Student Event Engineering Design Business Plan Cost Event Acceleration Skidpad Autocross Endurance Efficiency 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 6
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 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 8
Season 2015 - flüela 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 2 nd place in Formula Student Germany, 1 st places in Austria and Spain 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 9
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 Accumulator Capacity Gearbox Transmission Ratio Aerodynamic Sensitivities 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 11
Workflow Evaluation Concept idea Simulation 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 12
Workflow Car parameters m Simulate Calculate and analyze Event h L Visualize y x Velocity difference 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 13
Structure of the Simulation Model Powertrain / Tires Two-track model Control systems Driver 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 14
Structure of the Simulation Model Powertrain / Tires Two-track model Control systems Driver 6/3/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 15
Software Demonstration 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 16
Δv [km/h] Results Velocity difference of a 4WD car vs. a 2WD car 32 28 24 20 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 18 16 12 8 4 0
Points FSG Results Concept Simulation 700 600 500 400 300 200 Acceleration Points Skidpad Points Autocross Points Endurance Points Total 100 0 2WD, no Aero 2WD, Aero 2WD, DRS 4WD, no Aero 4WD, Aero 4WD, DRS 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 19
Points FSG Results Energy Simulations 4WD with DRS 650 700 600 645 500 640 400 300 635 200 630 100 Acceleration Points Skidpad Points Autocross Points Endurance Points Total 6250 5,5 5,7 5,7 5,9 5,9 6,1 6,1 6,3 6,3 6,5 6,5 6,7 6,7 6,9 6,9 7,1 7,1 Battery Capacity [kwh] 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 20
Validation Different tests were made to validate our results: Weight sensitivity validation Laptime deviation Lapsim On-track test Delta + 1 kg + 0.087 % + 0.082 % 6 % + 10 kg + 0.893 % + 0.821 % 8 % 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 21
Validation Different tests were made to validate our results: Weight sensitivity validation Aerodynamics sensitivity validation Laptime deviation Aero vs. no Aero Lapsim On-track test Delta 3.82 % 3.97 % 4 % 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 22
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. 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 23
MathWorks Support for Formula Student Complimentary Software MATLAB and Simulink Racing Lounge Online Training for Physical Modeling 5/10/2016 Akademischer Motorsportverein Zürich Fabrice Oehler 24
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