Control-oriented aspirated masses model for variable-valve-actuation engines

Modelling the cylinder filling process on variable-valve-actuation equipped spark-ignition engines is addressed in this paper. It is developed using first principles equations for the aspirated gas masses. These analytic equations include cylinder-peripheral thermodynamic conditions along with the intake and exhaust valve lift histories. Following a general formulation of the breathing phenomenon, a versatile model is proposed for any type of variable valve gear device. Two particular cases of variable-valve-timing and camless equipped engines are detailed. The model is calibrated using experimental data obtained at test bench. For both cases, good representativeness of the model shows the relevance of the approach.