基于自适应模糊滑模控制的主动队列管理算法

针对TCP这样大型复杂的网络系统的拥塞问题,考虑系统中存在的不确定因素是未知非线性的情况,设计了一种采用自适应模糊滑模控制理论的主动队列管理算法。该算法基于网络模型的特殊性,构造了Lyapunov-Krasovskill函数,设计了滑动模面,并基于线性矩阵不等式的方法给出该系统鲁棒渐近稳定的充分条件,所设计的自适应模糊控制律能够使系统的状态轨迹在有限时间内到达滑动模面。仿真结果表明,该算法在网络条件变化的情况下,能实现准确的跟踪目标队列长度,避免网络拥塞的发生。

Active Queue Management Algorithm Based on Adaptive Fuzzy Sliding Mode Control

For the problem of congestion control in TCP complex systems with unknown nonlinear disturbance,an active queue management (AQM) algorithm was investigated based on adaptive fuzzy sliding mode control (AFSMC).Sliding surface was constructed based on a Lyapunov-Krasovskill method for the particular network model.A sufficient condition was proposed for robust asymptotic stability of the system in terms of linear matrix inequality (LMI);the corresponding reaching law was designed,which could drive the state trajectory of system onto the sliding surface within limited time.The simulation results show that it can track queue length very quickly under various network conditions,and avoid the problem of dynamic network congestion.