Integration of intermittent measurement from in-cylinder pressure resonance in a multi-sensor mass flow estimator

This paper proposes three different methods to estimate the low-pressure cooled exhaust gas recirculation (LP-EGR) mass flow rate based on in-cylinder pressure measurements. The proposed LP-EGR models are designed with various combustion parameters (CP), which are derived from (1) heat release analysis, (2) central moment calculation, and (3) principal component analysis (PCA). The heat release provides valuable insights into the combustion process, such as flame speed and energy release. The central moment calculation enables quantitative representations of the shape characteristics in the cylinder pressure. The PCA also allows the extraction of the influential features through simple mathematical calculations. In this paper, these approaches focus on extracting the CP that are highly correlated to the diluent effects of the LP-EGR, and the parameters are used as the input states of the polynomial regression models. Moreover, in order to resolve the effects of cycle-to-cycle variations on the estimation results, a static model-based Kalman filter is applied to the CP for the practically usable estimation. The fast and precise performance of the proposed models was validated in real-time engine experiments under steady and transient conditions. The proposed LP-EGR mass flow model was demonstrated under a wide range of steady-states with an R2 value over 0.98. The instantaneous response of the cycle-basis LP-EGR estimation was validated under transient operations.

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Air mass flow estimation in turbocharged diesel engines from in-cylinder pressure measurement

Experimental Thermal and Fluid Science ◽

10.1016/j.expthermflusci.2009.08.009 ◽

2010 ◽

Vol 34 (1) ◽

pp. 37-47 ◽

Cited By ~ 84

Author(s):

J.M. Desantes ◽

J. Galindo ◽

C. Guardiola ◽

V. Dolz

Keyword(s):

Mass Flow ◽

Diesel Engines ◽

Pressure Measurement ◽

Cylinder Pressure ◽

Air Mass ◽

Flow Estimation

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Physical Model for Real-Time Simultaneous Estimation of Intake Mass and Cylinder Pressure in an SI Engine

ASME 2016 Internal Combustion Engine Fall Technical Conference ◽

10.1115/icef2016-9396 ◽

2016 ◽

Cited By ~ 1

Author(s):

Shuonan Xu ◽

Zhe Wang ◽

Robert Prucka ◽

Zoran Filipi ◽

Michael Prucka ◽

...

Keyword(s):

Real Time ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Air Flow ◽

Estimation Algorithm ◽

Simultaneous Estimation ◽

Cylinder Pressure ◽

Pressure Transducers ◽

Prediction Techniques

Stringent emission regulations require spark ignited (SI) engines to operate at stoichiometry to enable the use of a three way catalyst (TWC). Thus, accurate prediction of the intake charge mass flow rate is paramount. Current speed-density air mass-flow prediction techniques require extensive calibration for predicting volumetric efficiency, while mass air flow (MAF) meter based approaches suffer from a loss of accuracy during transients. This work aims to provide an alternative, i.e. a model based air charge estimation algorithm that can reduce calibration effort and provide a universal solution across engine platforms. An additional objective is to minimize the number of required sensors and associated cost. The foundation is established with a 0-D physics-based air charge model, where air flow through intake and exhaust valves is modeled on a crank-angle basis, without the need to measure in-cylinder pressure. The proposed algorithm solves differential equations for cylinder pressure and mass flow rate in/out of the cylinder to simultaneously obtain instantaneous pressure and mass-flow estimations, hence eliminating the need to install cylinder pressure transducers. An additional benefit is the robustness of the new model, due to its ability to self-compensate for an error in the intake runner pressure or initial estimation of the cylinder pressure. The model has been validated with GT-Power simulations and steady-state engine tests with multiple actuator sweeps. Transient tests and real-time implementations were performed as well.

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