Analysis and control of delay-dependent behavior of engine air-to-fuel ratio

The paper analyzes the influence of the delay on air-to-fuel ratio (A/F) regulation in internal combustion engines. Two feedback controller architectures, an integral controller for the case of a fast A/F sensor and a feedback linearization controller for the case of a slow A/F sensor, are considered. The collocation method is applied to determine the stability and guaranteed rate of convergence regions (charts) in the space of engine and controller parameters and we demonstrate that these charts can be used to automatically schedule A/F feedback controller gains as functions of engine operating conditions. Linear matrix inequality (LMI) techniques are employed for the analysis of disturbance rejection properties of the controllers