CSI - Controlled Auto Ignition - the Best Solution for the Fuel Consumption - Versus Emission Trade-Off?

In recent years several new gasoline engine technologies were introduced in order to reduce fuel consumption. Controlled autoignition seems to be an alternative to stratified part load operation, which is handicapped due to it's lean aftertreatment system for world wide application.

The principal advantages of controlled auto ignition combustion under steady state operation - combining fuel economy benefits similar to stratified charge systems with nearly negligible NOx and soot emissions - are already well known.

With the newly developed AVL- CSI system (Compression and Spark Ignition), a precise combustion control is achieved even under transient operation. For compensation of production and operation tolerances a cost optimized cylinder individual control was developed. Completely new functionalities of the engine management system are applied. This lean GDI concept complies with future emission standards without DeNOx catalyst and can be applied worldwide.

This paper covers the practical application of the AVL CSI combustion system including the required valve actuation variability and the demanded control system for the real world operation in a passenger car vehicle.