Observer designs for a turbocharger system of a diesel engine

We consider observer designs for an exhaust-gas turbocharger based on a third order nonlinear model of the air path of a diesel engine. To propose an observer, the system is analyzed in view of different observability properties for nonlinear systems. We derive explicit constraints for the system state guaranteeing observability. Based on that we design a high-gain observer and a sliding mode observer for the system. The performance of both designs has been assessed through a simulation study

Nonlinear observer design for turbocharger in a SI engine

Estimation of major turbocharger variables is essential for proper control and monitoring of a turbocharged engine. This work presents a novel algorithm to estimate turbocharger rotator speed, air temperature downstream a compressor and flow rate over the compressor using mean value models of engine subsystems. A nonlinear Luenberger observer is designed for a 1.7-lit gasoline turbocharged engine. The designed observed is shown analytically to be asymptotically stable. Performance of the designed observer is experimentally validated with the data collected from the engine. The results indicate the observer can capture major turbocharger\u27s rotational dynamics and estimated turbocharger variables are in a good agreement with the experimental measurements. © 2013 AACC American Automatic Control Council