The Design Of ARM-Based Networked Control System Expriment Platform And Researches On Control Strategy

Networked Control Systems ( NCS ) are distributed control systems which have sensors,actuators,and controllers interconnected by communication networks.Networked Control Systems are the integration of network communication technology and classical automatic control technology.The systems are playing more and more important roles in large scale control system,space probe,naval ships, automobiles and so on for its low prices,easy maintainability.But the transmissions through the Internet can cause the random,time-variant and uncertain delay of the sensing information and control information.The existence of these delays can cause the decline of system performances so much as the unstability of the whole system and bring difficulties to the analysises and design of Networked Control System.IP protocol based Networked Control System,especially the Internet based Networked Control System enlarge the application of classical Networked Control System.The utilization of Internet in the Networked Control System determines the different characteristics of network transmission.In this paper,aiming at the IP protocol based Networked Control System,especially the Internet based Networked Control System,Some researches have been conducted,and some achievements have been acquired.And in order to overcome the disadvantage of current researches on Networked Control System which emphasize particularly on theory and little on experiment, an ARM based experiment platform of Networked Control System has been designed to provide the verification of control strategies on Networked Control System in the realistic network.Main contributions are as following:(1) The detailed presentation of the researches in Networked Control System is provided.(2) Compare the different prediction methods of network induced delay in the Internet and introduce the wavelet theory ,combined with classical time series analysis theory, into the prediction of network induced delays in the Networked Control System ,the effectiveness of this method is verified by the use of MATLAB.(3) On the base of former prediction method,Smith control strategy is utilized to improve the system performances of Internet-based Networked Control System.With the help of MAT- LAB,the effectiveness of this control strategy is verified.(4) The design methods of the whole experiment platform and software and hardware implementations in a embedded networked control system are provided.To satisfy the needs of the tasks,software simulation and actual devices experiments are adopted in the embedded networked control system.(5) To meet the increasing demands of performances of the actuators,The implementation of ARM7 based embedded control platform and port of the uClinux operating system to the ARM7 processor have been studied.(6) the whole research work is evaluated objectively and the creativity and insufficiency is pointed out.The prospective for further research is given in the end.