In-Cylinder Peak Pressure Position Modelling

Abstract Higher efficiency demands and decreasing cylinder pressure sensor costs increase the opportunity for cylinder pressure based engine control. Control of spark advance using cylinder pressure has been widely examined in the literature and has been shown to be a suitable method of achieving minimum spark timing for best torque in variable environmental conditions. This paper summarises the peak pressure position control problem and the identification of forward and inverse NARMAX models for a range of engine speeds for use in such control. The models presented relate the spark advance, air bleed valve duty and the crank angle at which the peak cylinder pressure occurs and are developed for a single cylinder of a 1.6L Ford Zetec engine. The models established are valid over a range of engine speeds at a single initial load condition. The forward model may be used in controller evaluation and design. The inverse model may be used as an open loop controller or in plant linearisation to allow the application of linear feedback control techniques.