Robust Stabilization of State and Input Delay for Active Queue Management Algorithm

In this paper, we propose a design of an active-queue-management (AQM) scheme based on delay dependent sliding-mode-control (SMC), which is aimed at robust stabilization of network system with delay in both the input and state variables. A sliding surface that is based on a predictor has been designed to minimize the effect of the input delay. An AQM controller is derived to ensure the existence of a sliding mode on the surface. A maximum allowable value for the time delay of the system has been found under the AQM controller, uniformly bounded. Simulation experiments have been carried our and the results demonstrate this scheme can achieve transient and steady-state responses. The results also show that this scheme outperforms the known ones with the traditional either proportional-plus integral or sliding-mode controls.