Design of Flow Control Algorithm for Internet-based Networked Control Systems

• Main Authors: Tz-Yuan Ya, 葉子源
• Other Authors: Chwan-Lu Tseng
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/my52b9

碩士 === 國立臺北科技大學 === 電機工程系所 === 94 === Using Internet to deliver information or control message can not only reduce the complexity of wire lines but also allow for carrying out the remote control. Consequently, applications of the Internet-based Networked Control System (INCS) become the main stream of researches. Due to the essential characteristics of data-transmission delay, INCS design has to consider the delay characteristics, especially in feedback control system design. After comparing delay characteristics of TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and recently proposed CSTP (Control System Transfer Protocol), this thesis proposes a new fuzzy flow control algorithm which is suitable for INCS data transmission. It is known that the network status varies according to the fluctuation of the data transmission depending on place and time. Based on the round trip time and the corresponding variation, the proposed algorithm adopts the genetic algorithm and fuzzy control method to adjust the packet''s sending rate at sender, and thus the sender can real-time self-adjust the flow to improve the uniformity of transmission delay. Finally, to verify the effectiveness of the proposed method, NS2 and Matlab software are integrated to build up the simulation platform. From the results of the simulation, it can be found that the proposed mechanism can reduce the transmission delay and improve the uniformity of delay. As a result, the stability and dynamical behavior of the closed-loop system are also improved.