Air path control of a Turbocharged diesel engine: Fuzzy approach

This paper addresses the modeling and control of the air path system of a diesel engine equipped with Exhaust Gas recirculation (EGR) and Variable Geometry Turbocharger (VGT). The goal is to control carefully the air flow to reduce emissions of pollutant particles and fuel consumption. First, T-S Fuzzy model is employed to represent the nonlinear system diesel engine. Secondly, based on T-S fuzzy model, a fuzzy observer design and H_∞ controller design is proposed using a two-step approach to calculate the controller and the observer gains. Sufficient conditions are derived for asymptotic output tracking controllers in the format of Linear Matrix Inequalities (LMIs). Then, a single step approach is studied: the proposed approach considerably simplifies the design procedure and gives in only one step the controller and the observer gains. Both methods are applied to the system diesel engine. The effectiveness of the single approach is demonstrated through numerical simulation results.