Research On Estimation Algorithm Of Time-delay In Networked Control Systems Based On The Internet

Networked Control System (NCS) is an integration of networkingcommunication technology and cybernetic theoretic. A NCS connects the controllers,the sensors and the actuators through one shared networking to form feedback controlloops. Information is transmitted by network in the NCS. Compared with traditionalcontrol systems, the NCS has advantages of wide control area, high reliability, goodflexibility, easy malfunction finding and simple installation and maintenance, etc.Along with the fast developments of network technologies, especially Internettechnology, NCS based on Internet, which is the development direction of the controltechnology, has been a hot research problem at home and abroad.Compared with traditional control systems, communication network has beeninserted in NCS. Some new issues such as time-delay, clock synchronization and lostof packets. These problems make the NCS's control quality worse, and sometimemake NCS become instability.In this thesis, end-to-end delay of the Internet is talked about with emphases.End-to-end delay of the Internet is an important factor to evaluate the quality of thenetwork. Due to the fact that the clocks at end systems are usually not synchronizedand running at different speeds, experimental data have to be processed with somealgorithms to get the true delay.In this thesis, after valid analysis of experimental data, a Dynamic LinearAlgorithm (gradual subsection linear method) is proposed to estimate and remove theerror in the experimental data. Efficiency of this algorithm is proved by experiments.This algorithm can also be used in online measurement.