Robust controller design for active queue management system

This paper is concerned with the robustness of AQM controller in internet congestion control. For the parameter variety and disturbance in TCP/IP network, a robust H_∞ optimal AQM controller is designed based on uncertain time-delay model of the systems. The existence condition of the observer is obtained by applying Lyapunov method and matrix inequalities, and the design method of the feedback controller via the observe state is presented. The robust stability and the effect of interference restraint in the presence of network parameter variety and disturbance is validated and tested through simulations.