Analysis of Potential of Sailing Functionality in Indian Driving Conditions
Published February 1, 2016 by SAE International in United States
Annotation of this paper is available
Sailing Function allows a vehicle to roll freely without traction force, using an automated powertrain/clutch control strategy- when power demand from internal combustion engine is low. Currently in AMT/MT, during coasting phase with clutch and gear engaged, ECM requests a ‘Fuel-Cut’ - where additional vehicle kinetic energy is spent in overcoming Engine friction losses (loss as heat from friction). To avoid this, the drivetrain can be disconnected from Engine - by actuating the clutch, or engaging neutral or both -popularly called sailing - thereby increasing rolling distance. This study focusses on the various aspects of developing a sailing strategy suitable for Indian Conditions - driving pattern, road and traffic conditions. Sailing timeshare - or the amount of time spent in this state was evaluated in flat and hilly driving conditions. Estimation is made about the potential impact of this technology on real world fuel economy of the vehicles, in comparison to the conventional Fuel cut based technology, Idle Start Stop technology and Coasting start stop technology. The impact of this technology on the driver - in terms of drivability and safety is quantified. A testing cycle, which can used to compare various sailing strategies, is proposed.