shashikanth suryanarayanan tr35
TRANSCRIPT
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