Long term stoichiometric Air/Fuel Ratio (AFR) control of an SI engine is at the present mainly maintained by table mapping of the engine's fresh air intake as a function of the engine operating point. In order to reduce a stationary error in the AFR to zero the table based control normally works in conjunction with a PI feedback from a HEGO sensor. The effective bandwidth of this feedback loop is quite small, generally around 2 Hz. This is altogether too small for accurate AFR control.This paper presents a new lambda control methodology (H-infinity) which has a somewhat larger bandwidth and can guarentee robustness with respect to selected engine variable and parameter variations.
|Title of host publication||SAE Technical Papers no 1999-01-0845 and SP-1419|
|Place of Publication||Warrendale PA USA|
|Publication status||Published - 1999|
|Event||SAE International Congress & Exposition 1999: Diesel exhaust aftertreatment - Detroit, United States|
Duration: 1 Mar 1999 → 4 Mar 1999
|Conference||SAE International Congress & Exposition 1999|
|Period||01/03/1999 → 04/03/1999|