基于模糊滑模控制的主动队列管理算法

Active Queue Management Algorithm Based on Fuzzy Sliding Mode Control

针对动态网络的拥塞问题,提出一种主动队列管理(AQM)算法·该算法基于模糊滑模控制器(FSMC)设计,适合于动态网络流量的变化·模糊控制的加入,缩短了到达时间,改善了滑模控制的抖振现象·对于TCP/IP网络中存在的网络模型的不确定性、网络参数的时变性以及非TCP适应流所引起的网络抖动,该算法具有很强的鲁棒性·仿真结果表明该方法可以使队列长度快速收敛到设定值,同时维持较小的队列振荡,尤其是在网络条件变化的情况下,该算法优于传统的PI控制、模糊控制和传统的滑模控制·

Based on fuzzy sliding mode control （FSMC）, an active queue management （AQM） algorithm adaptable to the change of dynamic network flow is presented to ,solve the problems of dynamic network congestion. With the fuzzy control introduced in, the arrival time is shortened and the jitter from sliding mode control is improved. The algorithm shows its high robustness to the nonlinear control problems in TCP/IP networks, such as modeling uncertainties, fluctuation of time-varying parameters and jitter of network due to the flow unadaptlve to TCP model, Simulation results demonstrated that this method enables the queue length to converge at a preset value quickly and keeps the queue oscillation small and, in particular, the algorithm proposed outperforms the conventional PI control, fuzzy control and sliding mode control if the network conditions change.