Sliding mode control of delayed systems with application to engine idle speed control

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 delayed system is asymptotically stable with SMC based on the delay-free system. The method is applied to the internal combustion engine idle speed control problem dealing with the induction-to-power delay inherent in the plant. Both the simulation and experimental results show the efficiency of the approach and demonstrate the controller's capability of disturbance rejection.