Shashikanth Suryanarayanan TR35

Shashikanth Suryanarayanan

Assistant Professor, Department of Mechanical EngineeringIIT Bombay, Powai, Mumbai 400076

Founder & Director, SEDEMAC Mechatronics Pvt Ltd

Separating Decision Making from Actuation

Steer-by-Wire with Independent Steering

EMS for petrol-powered small engines

Steer-by-Wire (SBW)

SBW: No mech linkages between handwheel and roadwheels

Traditional Steering Systems Steer-by-Wire

Steer-by-Wire (SBW) with Independent Steering

“Handwheel” system can be configured to provide steering feel of choice

• “Little finger” Steering Possible

• Feel of a traditional steering system possible

Roadwheels independently steered; Departure from Ackermann Geometry

Spread-Eagle Position

Knock-knee Position

Aug 8, 2008

4/18

A Scorpio Retrofitted with India’s First Steer-by-Wire System

• For one of the tests, made to feel like a conventional vehicle

• Roadwheel system retrofit

Emission Regulations for Small Engines

Year 2-wheeler (g/km) 3-wheeler (g/km)

CO HC+NOx CO HC+NOx

1991 12-15 8-9 30 12

1996 4.5 3.6 6.75 5.4

2000 2 2 4 2

2005 1.5 1.5 2.25 2

2008/10 1 1 1.25 1.25

Rapidly tightening emission norms

Anything below 0.6-0.7 g/km difficult to meet w carburettors

Going Forward: Carburettors out, Fuel-injection in

Fuel-injection allows for accurate fuel metering

Sep 12, 2007

6/30

Typical Catalyst Conversion EfficacyTypical Catalyst Conversion Efficacy

Maintaining air-fuel ratio close to

stoichiomety

Reduced CO, HC, NOx emissions

Fuel-Injection and Accurate Fuel Metering

Orchestration of fuel injection and sparking requires EMS

EMS: Sensors + Actuators + Control unit (ECU)

Design Drivers: High fuel economy, good drivability, low emissions

IIT Bombay Small Engine EMS

Battery

Fuel Injector To Spark PlugElectronic

Control Unit(ECU)

FromVehicle

SensorsFuel Pump

What’s new? Minimal Sensing Architecture Reduced costsMade possible through exploitation of small engine physics

Protos of ECUs tested by 2-wheeler OEM on chassis dyno 75% ↓in engine-out HC as compared to carburettor 10% ↓in fuel consumption as compared to carburettor First successful, “from-scratch” concept effort in India leading to

demo of a high-performance fuel-injection ECU

Product realization by SEDEMAC -- venture-funded start-up