A sliding mode control (SMC) design method is proposed for a class of point
-delayed systems. A linear transformation is applied to convert the delayed
system to delay-free system whose spectra embed all the unstable poles of
the original system with given stability margin. It is proved that the dela
yed system is asymptotically stable with SMC based on the delay-free system
. The method is applied to the internal combustion (IC) engine idle speed c
ontrol problem to deal with the induction-to-power delay inherent in the pl
ant. Both simulation and experimental results show the efficiency of the ap
proach and demonstrate the controller's capability of disturbance rejection
.