Unscented MPC Design for Turbocharged EGR System in Diesel Engines

Exhaust gas recirculation (EGR) has become an integral part of the NOx emission reduction mechanisms utilized in modern combustion engines. However, capabilities to recirculate the processed gas are oftentimes compromised by the inability to surmount the pressure differential between the intake and exhaust manifolds. The issue is dealt with successfully by the turbocharged EGR system discussed in this article. The increased complexity of such an EGR system requires a multivariable control system in order to achieve the EGR set-point tracking across the desired operating range. In this work, model predictive control is used to naturally incorporate the information about system internal couplings via the prediction model. The states of the partially observed EGR system are recovered by using the unscented Kalman filter. Finally, the designed unscented MPC (UMPC) system is validated by numerical simulations.