Observer-based control design for diesel engines via LMI

This work deals with the problem of observer-based controller for diesel engines. The control objective is to regulate the intake and exhaust manifold pressures and the compressor power in a four-cylinder diesel engine in order to obtain low emissions and low fuel consumption. The considered mean value model of the air path system is rewritten as a nonlinear system with varying parameters. The proposed design method allows to determine simultaneously the observer and control gains based on the Lyapunov theory and the Young´s inequality. In addition, the modified mean value theorem (MMVT) is used to express the nonlinear error dynamics as a convex combination of known matrices with time varying coefficients. The sufficient conditions are expressed in terms of linear matrix inequality (LMI). Performances of the proposed approach are shown through the application to a diesel engine model.