Adaptive Air Charge Estimation for Turbocharged Diesel Engines Without Exhaust Gas Recirculation

Abstract

The paper presents an adaptive observer for in-cylinder air charge estimation for turbocharged diesel engines without exhaust gas recirculation (EGR). We assess the observability of the mean value engine model when the intake manifold pressure and the compressor flow are measured, and the performance of the observer is compared to existing schemes analytically and with limited simulations. Specifically, it is shown that the designed observer performs better than the conventional schemes during fast step changes in engine fueling level, eventhough it uses a simple but time varying parameterization of the volumetric efficiency. Furthermore, the estimate is less sensitive to changes in engine parameters than the existing schemes.