Improved Dynamic Performance of Turbocharged SI Engine Vehicles due to Clutch Actuation

Abstract

This article describes two strategies developed to tackle the problem of the turbo lag in spark-ignited turbocharged engines. A representative test case for the dynamic behavior and a simple cost functional are derived as well.A mean value model is used to optimize the dynamic behavior of the turbocharged engine. This leads to two strategies which either rely on a variation in spark timing or on an additional actuation of the clutch. The latter serves to substantially improve the acceleration phase in terms of time and comfort both. The clutch strategy allows a reduction of the time lag to reach 90 % of full load torque by more than 0.9s.