Software development in an electric vehicle:

the TU/e Lupo EL

ir. Paul van OorschotMechanical Engineering, Dynamics and Control

October 3, 2011, Eindhoven

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TU/e Lupo EL

• picture + specs

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Donor vehicle: VW Lupo 3LVehicle mass: 1060 kg Battery capacity: 27 kWhTop speed: 130 km/hRange: up to 200km, 170km@100km/h0 – 100 km/h: 12 sec.4 seats

Carrying energy in batteries

energy density• batteries

weight: 273 kgvolume: 180 literscapacity: 27 kWh

• equivalent fossil fuel: 10 L petrol (8 kg), 7 L diesel (6 kg)

energy flow• normal fuel pump: 40 L/minute

• normal socket (Europe: 3.6 kW): approx. 1.5 L petrol/hour (1600x slower)

• DC fast charging (50 kW, CHAdeMO): approx. 20 L petrol/hour (120x slower)

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System overview

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Chassis 598 kg

ICE = 239 kgFocus points:

• Lightweight• Efficient• Flexible control• Extensive measurement abilities

Electric vehicle system diagram

Packaging

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• No interior space lost

• Weight distribution improved

Front compartment

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Aluminium mounting and battery box design

Charger

Inverter

DC-DC 12V

Controller

IFM CR0232 PLC

80x IO ports

4x CAN bus

Electric system layout

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VW systems fully functional (CAN)

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Controller

IFM CR2032, Industrial PLC• Infineon TriCore 1796, 32 bit CPU, 150 Mhz• 32 Inputs (analog/digital)• 48 Outputs (PWM, high/low side, current controlled)• 4 CAN bus interfaces (2.0 A/B, up to 1Mbit/s)

Software• CoDeSys v2.3 software development platform• IEC 61131-3 based, following languages available

• Instruction list (IL)• Structured text (ST)• Ladder diagram (LD)• Function block diagram (FBD)• Sequential function chart (SFC)

Control and safety features

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ABS active ? -> Disable regenerative braking

Airbags(crash) -> Disable systems and HV

Door opened ?• Initialize safety systems• Isolation monitoring• Brake booster vacuum

Data Aquisition

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Real-time logging via CAN bus

Extensive data on:• Energy flows• Battery condition• Vehicle dynamics

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PLC cycle setup

Cycle time ≈ 7 ms

Inputs read, values determined> 50 CAN identifiers> 200 parameters stored in structs

Sequential function execution• Functions in order of priority• Higher priority overrides

Outputs temporarily stored• Outputs sent at end of cycle

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Traction

Enable traction (start the vehicle)

Traction control

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Regenerative braking

Brake pressure

Current limit

Regenerative braking control• Based on brake system pressure• Torque controlled (better brake blending)

User interface

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Original VW console Touchscreen computer• Energy flows to components• Measured data per component• Errors and warnings• Charging control

Battery SOC

Power (-30 to +50 kW)

Energy consumption

Speed

Visual and audible indication• Ready to drive• Traction enabled while door open• System errors• HV disabled

Thank you for your attention!

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