Design of the dual closed-loop flow rate controller based on H-infinity optimization theory for computer networks

摘要

Aiming at the deficiency against disturbance of flow rate controllers proposed formerly, the dual closed-loop flow rate controller based on H. optimization theory is proposed for the congestion control in computer networks. The design against disturbance is separated from the design of setpoint response to enhance the abilities against disturbance and mis-modeling. The designed optimization controller can implement Dahlin algorithm approximately, which can overcome the adverse effect caused by time delay effectively. Moreover, the definite formula is given between the stable margin and parameters of the controller. The proposed scheme can make the buffer queue level in bottleneck node stabilized on a setpoint quickly and the link bandwidth shared weighted-fairly. A number of simulations are done to verify the theoretical analysis and demonstrate the performance of the designed controller. Besides, the relationship between the robustness and the transient response of the flow rate control system is analyzed qualitatively. (C) 2003 Elsevier B.V. All rights reserved.