The advance combustion control in a hybrid SI/HCCI engine by using ion current sensing

In a future ‘hybrid mode’ SI/HCCI engine transition between these modes, over the operating map, will play a crucial role. The engine management system must provide a fast and smooth transition between these two modes, hence a new combustion feedback based control system is needed. The aim of this paper is to investigate the use of an ion-current sensor in SI/HCCI engine for direct combustion feedback control. The experimental results obtained, at different speed and loads, show that the estimation of cylinder pressure, through the ion signal, can be performed with high accuracy, and that ion-current has the potential to be a cost effective solution for direct combustion control.