Haris Hamedovic

IMEP-Estimation and In-Cylinder Pressure Reconstruction for Multicylinder SI-Engine by Combined Processing of Engine Speed and One Cylinder Pressure

In order to optimize the performance and emission of engines, advanced control and diagnostic systems require detailed feedback information about the combustion process. In this context, cost-effective solutions are of interest. The contribution describes a method for reconstructing cylinder-individual features of each combustion cycle by processing the instantaneous fluctuations of the engine speed and the in-cylinder pressure of one cylinder. Model-based torque estimation, analyzing both of the signals simultaneously, provides an accurate estimation of the mean indicated pressure. Using this method, a new algorithm for advanced misfire detection is presented. Furthermore, a new pressure model with a feasible number of parameters is proposed. It is combined with the torque estimation in order to reconstruct the unknown pressure traces of the cylinders not equipped with sensors. Measurement data obtained from a vehicle with a four cylinder Sl-engine is used to demonstrate the performance of the methods over the whole range of engine speed and load.

Evaluation of torque estimation using gray-box and physical crankshaft modeling

In-cylinder pressure and combustion torque provide feedback information that can be utilized in advanced control and diagnosis strategies for combustion engines. One challenge in torque estimation is the compensation of the torsional effects of the crankshaft. This paper presents a novel torque estimation method using a gray-box model (motivated from a physical model) of the crankshaft in combination with one in-cylinder pressure and one engine speed measurement. The MISO system inversion is described and the approach is benchmarked against an existing method. The results using a four- cylinder spark ignition engine encourage the further investigation of the approach.

In-cylinder pressure reconstruction for multicylinder SI-engine by combined processing of engine speed and one cylinder pressure

The paper presents an approach to reconstruct cylinder-individual pressure of each combustion cycle by processing the instantaneous fluctuations of the engine speed and the in-cylinder pressure of one cylinder. A new pressure model with a feasible number of parameters is combined with a model-based torque estimation in order to reconstruct the pressure traces. The performance of the proposed algorithm is demonstrated with measurement data acquired from a vehicle with a four cylinder spark ignition (SI) engine.