New results on feedback stabilization of diesel engines

This paper presents a model-based control strategy for the engine speed trajectory tracking and the control of the Exhaust Gas Recirculation (EGR) flow and Variable Geometry Turbocharger (VGT) flow. The engine speed is modeled as a non-linear model containing explicitly the expression of the fuel conversion efficiency. Generally speaking, in literature, its modeling obtained from experiments has two main expressions defined as polynomial or exponential forms. This paper focuses on the engine speed stabilization when the fuel conversion efficiency is modeled with the exponential form which is more realistic in the case of passenger cars. This work proposes a new smooth stabilization law around a desired engine speed value. On the other hand, a second loop is added to control the EGR and VGT flows. Simulation results are proposed to highlight the closed-loop control accuracy.