Studies And Developments Of Real-Time Communication In Industrial Wireless Networks

Recently, as the gradually mature and extensive application of wired-networks, the problems and the limitations it encountered in some special circumstances are standing out. More and more people are turning to the research of wireless networks that will be the substitutes of wired networks that would not be available in some circumstances.In the field of industrial control, as the complex environment of the scene, some wired-medium will normally be affacted by some factors such as high temperatures, high humidity, corrosion and should not be laid. Wireless networks make up for this shortcoming and has laid a Basis for the advent of the all-IP industrial age. Although the Internet in real life has been to reach every household, but being applied to industry is not an easy task. The first problem is the real-time transmission of information, which is the main obstacle of putting the network into the industrial area. In Ethernet, there have been a number of real-time communication model, through the efficient real-time clock synchronization and scheduling algorithm the uncertainty of networks has been basically solved. Therefore, what wireless networks are facing and the urgent needed to be solved is still this problem.This paper analyses the characteristics of wireless technology, combined with the characteristics of the industrial control area and proposes a few of key issues. By comparing several advantages and disadvantages of the existing wireless network, it finalized the network model based on the IEEE 802.15.4 MAC/PHY and also developed the hardware drivers and software platforms, and conducted a series of experimental verification of its feasibility.On the basis of the results we researched and developed the industrial wireless networks real-time communication platform and took clock synchronization and communication scheduling as key points. According to the understanding of wireless networks in industrial application and taking advantages of existing research results, we designed and developed the wireless network synchronization algorithm and the communication algorithm based on levels, at the same time proposed the local clock self-correcting synchronization method to solve the problem of local network nodes clock frequency drifting. All algorithms are experimented on the physical nodes and the results can basically meet the needs of the industrial demand for real-time communication network.