摘要
提出一种基于Smith预估的模糊-PI双模控制器的主动队列管理算法S-Fuzzy2PI。将模糊控制与PI算法相结合,系统误差较大时采用Fuzzy控制用以加强系统的响应速度和鲁棒性,系统接近稳态时切换到PI控制器来加强系统的稳态特性。网络拥塞控制系统是一个时滞系统,回环时间(RTT)较大时,算法性能受到较大的影响,因此本文引入Smith预估器来克服大时滞网络对于系统性能的影响。NS2仿真结果表明:S-Fuzzy2PI算法在瞬态性能和稳态性能上都有很大的改进,有效地克服了大时滞网络带来的负面影响。
A new algorithm for AQM is proposed based on the Smith predictor and Fuzzy2PI control（S-Fuzzy2PI）. S-Fuzzy2PI combines PI controller with fuzzy controller. When congestion level is high, this paper uses fuzzy controller to improve the quick convergence speed and strong robustness. And when congestion level is lower, this paper uses PI controller to improve the stability. As the network congestion control system is essentially a delay system, so it brings up Smith predictor to overcome the negative impact on stability by large delay. The network simulation （NS2） results show that the transient response and tracking capability of the S-Fuzzy2PI is better, which is more suitable for the changing and large delay network system.
出处
《计算机与现代化》
2009年第10期14-17,共4页
Computer and Modernization
