Article ID Journal Published Year Pages File Type
559170 Mechanical Systems and Signal Processing 2016 13 Pages PDF
Abstract

•A method for inferring the trapped mass from resonance is developed.•The few signals used by the method ensure obtaining small sensor errors.•The method developed permits one cycle resolution without using flow assumptions.•Obtaining many trapped mass measures along a cycle permits an error metric.

High pressure gradients at homogeneous charge compression ignition (HCCI) engines heavily excite the pressure resonance. The pressure resonant frequency depends on speed of sound in the cylinder, and thus on the bulk gas temperature. Present paper profits this relation estimating the trapped mass inside the cylinder. In contrast to other estimation methods in the literature, the presented method is based on the trace of the in-cylinder pressure during the cycle; therefore, it permits a cycle-to-cycle mass estimation, and avoids errors associated with other assumptions, such as heat transfer during compression or initial temperature of the in-cylinder gases. The proposed strategy only needs the pressure signal, a volume estimation and a composition assumption to obtain several trapped mass estimates during one cycle. These estimates can be later combined for providing an error estimate of the measurement, with the assumption of negligible blow-by. The method is demonstrated in two HCCI engines of different size, showing good performance in steady operation and presenting great potential to control transient operation.

Related Topics
Physical Sciences and Engineering Computer Science Signal Processing
Authors
, , , ,