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Presented in this paper is an adaptive steady state fueling control system for spark ignition-internal combustion engines. Since the fueling control system is model based, the engine maps currently used in engine fueling control are eliminated. This proposed fueling control system is modular and can therefore accommodate changes in the engine sensor set such as replacing the mass-air flow sensor with a manifold air pressure sensor. The fueling algorithm can operate with either a switching type O2 sensor or a linear O2 sensor. The steady state fueling compensation utilizes a feedforward controller which determines the necessary fuel pulsewidth after a throttle transient to achieve stoichiometry. This feedforward controller is comprised of two nonlinear models capturing the steady state characteristics of the fueling process. These models are identified from an input-output testing procedure where the inputs are fuel pulsewidth and mass-air flow signal and the output is a lambda signal.

Presented in this paper is a robust feedback controller design procedure to regulate the mass air flow (MAF) into a 4.6L V8 spark ignition engine. A system level model of engine throttle to engine mass air flow is experimentally determined. In addition, an H∞ controller is designed to control engine mass air flow with zero steady state error while addressing the nonlinear throttle characteristics and pure delay. The controller design methodology applied to the mass air flow control problem is discussed and an interpretation of the controller presented. Finally, engine dynamometer data demonstrates that the H∞ controller rejects noise and disturbances while meeting transient and steady state performance objectives.