Air-fuel ratio regulation using a discrete-time internal model controller

As the transportation systems become increasingly complex and crowded, more strict standards are proposed to reduce the levels of emissions produced by motor vehicles and hence the negative effects these emissions have on public health and the environment. The efficiency of three-way catalysts typically employed in Spark Ignition (SI) engines depends primarily on the Air-Fuel Ratio (AFR) regulation performance. We implement an Internal Model Controller (IMC) combined with an adaptive law in discrete-time and use this structure to address the AFR control problem despite the presence of parametric uncertainties.