Distributed Model Predictive Control of an Electrically Boosted Diesel Engine Air Path System

Abstract

This paper presents a distributed control design for an electrically boosted air path system of a Diesel engine. The proposed design aims at improving the transient response of the engine during acceleration, namely by coordinating the E-Booster, the variable geometry turbocharger (VGT) and the exhaust gas recirculation (EGR) actuators to regulate the intake and exhaust manifold pressures and EGR fraction to specified set points. Distributed Model Predictive Control is applied for the control design, based on a control-oriented model of the air path system. In such control architecture, the E-Booster and the remaining air path system actuators are separated into two interconnected local controllers, achieving plug-and-play capability of the E-Booster as well as smooth mode transitions. The proposed distributed control scheme is then evaluated in simulation, and comparing with a corresponding centralized control design. Two case studies are considered for verification, consisting of a step torque demand at constant speed and a tip-in acceleration transient.