Introduction• Spark Ignition ( SI ) Engine Control : Control of a SI engine for

the best fuel efficiency, low emission and good drivability is a

demanding control system problem.

• Classical control techniques like PID control can’t provide the

best performance over the entire operating envelop due to

highly non-linear behavior of the engine.

OBJECTIVES

• To design and develop the Engine Management System

(EMS) based on Neural Network based Fuzzy Logic Control

(FLC) / Model Reference Control (MRC) techniques to improve

the engine performance and reduce pollution.

• To reduce the controller tuning time with minimal number of

experiments

Engine Management System (EMS)

Engine Open Loop

Engine open loop response

• Engine Specification: 125 CC, 4-Stroke Port Fuel Injected (PFI) Gasoline Engine

Engine response for step spark time input (Open Loop)

15001600170018001900

2000210022002300

10 11 12 13 14 15

Time ( secs)

Sp

eed

(rp

m)

Spark time varied : 7.0 msec to 3.7 msec

Open Loop Idle speed response

1500

1550

1600

1650

1700

1750

1800

1 51 101 151 201 251 301 351 401 451

Cycle Number

Sp

ee

d (

RP

M)

Set Speed : 1700 (RPM)

Performance Graphs

Engine Test Results

• With closed loop Proportional Control of Spark Time Engine

Speed fluctuations was reduced, hence improved Noise,

Vibration and Harshness (NVH).

• Reduced Fuel consumption resulted in less Green House

gas (CO2) and HC emissions

Closed loop Idle response (P controller)

1500

1550

1600

1650

1700

1750

1800

1 35 69 103 137 171 205 239 273 307 341 375 409 443 477

Cycle Number

Sp

ee

d (

RP

M)

Set speed : 1700 (rpm), P gain: 10

Closed loop Idle response ( P - Controller)

1500

1550

1600

1650

1700

1750

1800

1 51 101 151 201 251 301 351 401 451

Cycle Number

Sp

ee

d (

RP

M)

Set Speed : 1700 (rpm), P gain : 18

Model Reference Idle Speed Engine controller

Proposed Model Based Controller

PID

Controller Engine

Speed SensorSignal Conditioning

Engine Reference Model

Reference Speed

Actual Speed

VMRC

Error

Speed

Spark Time

+

+

+-

Summary

• A low cost Microcontroller based Engine Management System (EMS) for a

single cylinder Spark Ignition (SI), Port Fuel Injected (PFI) was designed and

developed.

• The control algorithms for Classical PID and Fuzzy Logic control techniques

have developed and tested.

• The closed loop performance shows improvement in terms Idle Speed, Fuel

Consumption and Emissions.

• Test will be conducted to evaluate the performance of the Model Reference

Control algorithm over the conventional techniques.