8.1.2014. 4 STROKE ENGINE OPERATION Intake Stroke Compression Stroke Combustion Exhaust Stroke...
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Transcript of 8.1.2014. 4 STROKE ENGINE OPERATION Intake Stroke Compression Stroke Combustion Exhaust Stroke...
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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