Modeling, Identification, and Separation of Crankshaft Dynamics in a Light-Duty Diesel Engine
Paper in proceedings, 2009

Mathematical models of a torque sensor equipped crankshaft in a light-duty diesel engine are identified, validated, and compared. The models are based on in-cylinder pressure and crankshaft torque data collected from a 5-cylinder common-rail diesel engine running at multiple operating points. The work is motivated by the need of a crankshaft model in a closed-loop combustion control system based on crankshaft torque measurements. In such a system a crankshaft model is used in order to separate the measured crankshaft torque into cylinder individual torque contributions. A method for this is described and used for IMEP estimation. Not surprisingly, the results indicate that higher order models are able to estimate crankshaft torque more accurately than lower order models, even if the differences are small. For IMEP estimation using the cylinder separation method however, these differences have large effects on accuracy. Here, the performance of higher order models is significantly better than for lower order models. Also, models of odd model order perform better than models of even model order. On average, a 9th order model estimates IMEP values to within 2-3% of the reference values.

Author

Mikael Thor

Chalmers, Signals and Systems, Systems and control, Automatic Control

Ingemar Andersson

Chalmers, Signals and Systems, Signalbehandling och medicinsk teknik, Signal Processing

Tomas McKelvey

Chalmers, Signals and Systems, Signalbehandling och medicinsk teknik, Signal Processing

SAE Technical Paper Series 2009-01-1798, SAE 2009 International Powertrains, Fuels & Lubricants Meeting, Florence, Italy

Subject Categories

Control Engineering

Signal Processing

DOI

10.4271/2009-01-1798

More information

Created

10/7/2017