Effects of Engine Operating Conditions on In-Cylinder Air/Fuel Ratio Detection Using a Production Ion Sensing Device

Effects of engine parameters on ionization current and modeling of excess air coefficient by artificial neural network

“…According to the results of a previous study, the ionization current voltage increases by changing the AFR from a lean to stoichiometric value [27]. In addition, these results support the results obtained in previous works by Huang et al [5], Vressner et al [28], and Balles et al [29].…”

“…Cycle-resolved AFR and incylinder pressure were estimated using an ionization currentbased stochastic estimation method with a maximum 2% of errors by Lee et al [4]. The effects of the equivalence ratio, engine load, engine coolant temperature, and engine speed on the ionization current signal were investigated by Huang et al It was shown that the ionization current signal could be used with ANNs for the prediction of the equivalence ratio [5]. The estimation of the peak pressure position and AFR using the ionization current and ANNs was investigated by Wickstr€ om et al According to the results of this study, the estimation performance of the peak pressure position with ANN was two times better than a linear model and the estimation performance of the AFR with the ANN was 10 times better than the linear model [6].…”

A transient virtual-AFR sensor using the in-cylinder ion current signal

“…This use of NNs for AFR prediction has now been extensively researched [15,13,16,12,6,17]. Networks sizes and complexities have been determined through trial and error and estimation errors as low as 2% for 90% of test transients have been achieved [18].…”

“…The slope of this peak depends on the development of the flame and the derivatives of this show correlation to the AFR. Huang [12] characterized the in-cylinder ionization by the height and location of the peak and area under the ionization signal curve. Experiments were conducted using the Saab Trionic TM (Saab Automobile AB) production unit.…”

Assessment of the reliability of ionization current measurement in estimating peak pressure angle in a spark ignition engine

“…Further experiments 10,11 to estimate ion concentration in SI engines using the spark plug as Langmuir probe again showed an influence of air/fuel ratio on IC peak value during combustion. In the wake of these findings, the topic attracted increasing attention, with many studies, [12][13][14][15][16][17][18] with the objective of a cycle-by-cycle control of air/fuel ratio made possible by the development of engine electronic control.…”