Real-time Control of a Two-Stage Serial VGT Diesel Engine Using MPC

Real-time model predictive control (MPC) is used to experimentally assess the transient air-path performance of a two-stage serial variable geometry turbocharger (VGT) fitted to a light duty Diesel engine. The control model is based on a mean value engine model (MVEM) that is developed using data from the engine with a single stage turbocharger and modified to simulate the two-stage arrangement. A tip-in transient manoeuvre is used to assess system performance, in particular the boost-control where MPC is used to achieve close to optimal performance. This paper explores the improvement in transient performance when using two VGT turbochargers in series and considers where the differences between experiment and simulation occur.