Abstract
To provide an appropriate direction for development of transient control algorithm in a gasoline engine, transient performance analysis and evaluation under rapid accelerating and decelerating driving conditions were implemented by experimental study. In order to evaluate the characteristics of transient performance quantitatively, the concept and method by transient response specifications were introduced. Several performance parameters in terms of engine speed(RPM), mass air flow(MAF), manifold absolute pressure(MAP), fuel injection duration(¨·tInj) and air excess ratio(ǹ) were measured simultaneously during the rapid opening and closing of the throttle valve using the step motor controlled by PC. Transient response specifications and non-dimensional variables in terms of delay time rate, rising time rate and settling time rate characterized the transient performance of a gasoline engine quantitatively.