8.1.2014. 4 STROKE ENGINE OPERATION Intake Stroke Compression Stroke Combustion Exhaust Stroke Different Engine states require different air/fuel concentration,

Final Presentation

Engine Control Unit on SOC

By : Tamir Malka, Eliel PeretzSupervised : Mony OrbachSemester : Spring 14’

8.1.2014

4 STROKE ENGINE OPERATION

Intake StrokeCompression StrokeCombustion Exhaust Stroke

Different Engine states require different air/fuel concentration, different ignition advance

MOTIVATION

• Most modern car engines are 4 stroke engines.

To achieve maximum efficiency .

• the engine must be supplied with precise fuel amounts (Air-Fuel Ratio).

• fuel must be burn at the ideal time when the pistons move up and down (Ignition Advance).

• SoC are very cheap

For these – we need fast input and output access, in the ~10us range.

PROJECT GOALS

Design a real time system that reads engine sensors and :

• Determine the ideal spark time

• Determine the ideal air-fuel mixture

• enable easy updating of the ECU via the built in SD-CARD

• Affordable

• Designed for a 4cylinder engine

NAÏVE ARCHITECTURE

ECUSampling rate of 233hz !

SOLUTION : FINAL ARCHITECTURE

2nd Arduino

UARTDigitalAnaloginputs

SOLUTION : FINAL ARCHITECTURE

ECUOutputs :Fuel, Ignition pulses

Inputs :Engine sensors (MAP,CLT,IAT,CRANK,TPS,O2)

BLOCK DIAGRAM

Load Tables from SD-card

StreamSend RX

Calc Ign Adv , Inj PW

StreamSend TX

Read Sensors

StreamSend TX

StreamSend RX

Calc Inj , Ign times

Crank Sensor

Drive Outputs

ArduinoGalileo

Calc desired angle for

event

REAL TIME PROGRAMMING

Calc time untill event

Schedule event : time

to start, duration

Wait untill : current_time=interrupt_time

End funcStart funcinterrupt time=current_time+duration

interrupt time=current_time+time_to_start

TESTING ENVIRONMENT

ECUGalileo+Arduino Nano

D2: Crank (timerInterrupt driven)

LPF

PWM:MAPTPSCOOLANTIAT

Analog voltages

Each engine scenario is a different test bench code

Engine simulator

TEST SCENARIOS

• Accelerate – Increasing RPM. more sparks and increased fuel amount

• Decelerate – Decreasing RPM. less sparks and decreasing fuel amount

• Warming Engine – Increasing COOLANT. decreasing fuel amount.

• Slope – Increasing TPS. increasing fuel amount

• High Load – Increasing MAP. Increasing fuel amount

ACCELERATION SIMULATION RESULTS

WARMING ENGINE SIMULATION RESULTS

STEEP SLOPE SIMULATION RESULTS

DECELERATE SIMULATION RESULTS

HIGH LOAD SIMULATION RESULTS

NEXT STEPS?

engine1 engine2

serial0 serial1

NEXT STEPS?

engine1 engineN

I2c BUS

engine2

…

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