Technical Paper
Indicated Torque Estimation Using a Torsional Behavior Model of the Engine
2005-10-24
2005-01-3761
Effective and precise torque estimation is a great opportunity to improve actual torque-based engine management strategies. Modern ECU often already implement algorithms to estimate on-board the torque that is being produced by the engine, even if very often these estimation algorithms are based on look-up tables and maps and cannot be employed for example for diagnostic purposes; In other cases the obtained precision is not very high. This work presents the development of a torque estimation procedure based on the instantaneous engine speed measurement. The steps that allowed defining this procedure are briefly explained in the following. The definition of a model that describes the torsional behavior of the engine-load system made first possible to analyze the relationship between the corresponding frequency components of the instantaneous engine speed fluctuations and the indicated torque developed by the cylinders.