Study On Network Random Delay And It’s Influence Factors

With the development of science and technology, the complexity of production requires the original control system to combine with other technologies. New control systems have been created to meet the different needs of production and life. Among them, the networked control system which was combined by the original control system and Internet technology has advantages like resource sharing, simple structure, low cost, convenient maintenance and development, so it has achieved great success in the field of automation like agricultural production, aerospace, industrial production, transportation, as well as robotics. But at the same time, there are many issues in the networked control system. Due to the influence of communication protocol and network structure, the packet delay may be too large, the data packet may loss, packets may be disordered, and many other problems may appear. In this way, the control information can’t arrive at the controlled objection in time, so that the control effect of the whole system will be reduced. The nature of these problems is the network delay. Looking for the effective ways to study the delay of the network and reducing the delay to make it in a certain extent which can be controlled are both have a profound significance to the study of networked control system. Under such background, this paper uses OPNET to simulate the networked control system to study delay. Finding the influence factors of delay and predicting it on this platform. The main research contents of this paper are as follows:(1) This paper introduced the concept of networked control system, and analyzed the problems of system performance.(2) The simulation model of networked control system was built in OPNET. The comparative experiments were carried out by changing the code in OPNET and related parameters in the network.(3) The experiment results were analyzed in two aspects including waveform and data form. Finding out the law of delay and the related parameters which affecting the characteristic of delay in the network. Then put forward the idea of delay compensation.(4) This essay leads the concept of packet loss probability by the analysis of delay. The comparative experiments were carried out by changing the parameters in the network, then using the method of regression analysis to analyze the experimental data. Then this essay finds the relationship between the packet loss probability and the related parameters in the network. Finally, the feasibility of the relationship was verified by experiments.