Method and apparatus for determining air pressure in an engine.

摘要

A method of determining air pressure in the manifold of an engine comprises the steps obtaining a sensor signal representative of pressure inside the manifold; obtaining first and second filtered signals (ADMAPfast, ADMAPslow) from the sensor signal, the first filtered signal (ADMAPfast) being obtained from a filter having a relatively short time constant, the second filtered signal (ADMAPslow) being obtained from a filter having a relatively long time constant; determining whether the engine is operating under a substantially steady or a transient state; and determining a manifold absolute pressure (ADMAP) from one of or a combination of the first and second filtered signals (ADMAPfast, ADMAPslow) in dependence upon the engine operating state. The combined use of both filtered signals (ADMAPfast, ADMAPslow) provides a more accurate indication of engine load during both steady state and transient conditions, thereby enabling an engine management system to keep more closely to the stoichiometric air:fuel ratio. <IMAGE>