Model-based Selective Cylinder Deactivation Strategies in an Inline Four Cylinder Gasoline Engine

Abstract

Cylinder deactivation is a dominant engine management strategy for improving the fuel economy. However balanced engine operation under cylinder deactivation with Noise, Vibration, and Harshness (NVH) considerations is still a challenge for engines with inline configuration and small displacement volume. This paper presents a model-based approach of one and two cylinder deactivation in an inline four cylinder gasoline engine. A high fidelity gasoline engine model, is extended and then used to simulate the proposed individual cylinder power modulation strategy. The model of the torque producing mechanism in an inline four cylinder gasoline engine, derived using constrained equation of motion in Lagrangian Mechanism, is joined with a control oriented combustion model to obtain a novel model of the torque production subsystem of a four cylinder gasoline engine. Balanced engine operation with one and two deactivated cylinders is achieved using individual cylinder power modulation and NVH properties have been analyzed using Fourier Transform. The proposed approach can also be used to isolate and mitigate the effects of misfire in one cylinder.