  Diesel airpath controllers are required to deliver good tracking performance
whilst satisfying operational constraints and physical limitations of the
actuators. Due to explicit constraint handling capabilities, model predictive
controllers (MPC) have been successfully deployed in diesel airpath
applications. Previous MPC implementations have considered instantaneous
constraints on engine-out emissions in order to meet legislated emissions
regulations. However, the emissions standards are specified over a drive cycle,
and hence, can be satisfied on average rather than just instantaneously,
potentially allowing the controller to exploit the trade-off between emissions
and fuel economy. In this work, an MPC is formulated to maximise the fuel
efficiency whilst tracking boost pressure and exhaust gas recirculation (EGR)
rate references, and in the face of uncertainties, adhering to the input,
safety constraints and constraints on emissions averaged over some finite time
period. The tracking performance and satisfaction of average emissions
constraints using the proposed controller are demonstrated through an
experimental study considering the new European drive cycle.
