Air charge estimation for turbocharged diesel engines

The paper presents adaptive observers for in-cylinder air charge estimation for turbocharged diesel engines based on a mean value engine model. We assess the observability from various engine measurements. The performance of the observers is compared to existing schemes analytically and in simulations. Specifically, it is shown that the designed observers perform better than the conventional schemes during fast step changes in engine fuelling level. Furthermore, the estimate is less sensitive to changes in engine parameters than the existing schemes