Combustion Variation Feedback Control Approach for Multi-cylinder Spark Ignition Engines

Abstract

Lean-burn is an important advanced technology that is of benefit to the efficiency improvement of spark ignition (SI) engines. However, the combustion variation is a major barrier to achieving leaner air/fuel ratio. This paper presents an in-cylinder pressure-based multi-cylinder multi-variable combustion variation control strategy for SI engines, aims at controlling the combustion to the target heat release pattern (HRP). The combustion phase and total heat release are chosen as the control parameters which are controlled by adjusting spark advance (SA) and fuel injection mass, respectively. Two separate closed-loop statistical controllers are designed for SA and fuel injection control of single cylinder. The designed controllers are then applied to every individual cylinder. The effectiveness of the presented combustion variation control strategy is finally validated on a production four-cylinder SI gasoline engine at lean-burn mode.