| Industrial wireless network is a new wireless communication technology for low rate information communicates of the short-range between devices, which is started in 21st century. It is suitable for harsh industrial environment, with strong anti-jamming capability, ultra-low power, real-time communication and other technical features. It is an expansion and technological innovation of the existing wireless technology in industrial applications, and is a crucial technology to reduce the costs of industrial control systems and improve its application areas. WirelessHART is released by the HART Communication Foundation in late 2007, it is the first open wireless Mesh network communication protocol which is used in industrial automation and control systems. WirelessHART is a centralized control network, using a Network Manager to manage the network, which makes WirelessHART has three major advantages, simple, reliable and security. Compared with the wireless ad-hoc networks, centralized network with a Network Manager is capable of collect global network information, which makes it easier to obtain a more optimized network routing, easier to centralized schedule the communication resources, and the real-time communication in network can also be easily realized. In addition, centrally controlled network will help to avoid network conflicts. Finally, the existence of network manager can implement online maintains of the network, device can join and leave automatically.In a centralized network, scheduling and management scheme is the key to the efficient running of the network. This paper studies the scheduling of WirelessHART and the network management scheme. Firstly, the WirelessHART network routing algorithm is studied. After analysis of the network routing characteristics, different algorithms are proposed for Graph, Source and Broadcast routings. The proposed algorithms are based on BFS algorithm to guarantee that the obtained routing has the shortest routing path. In addition, the hop level redundancy of Graph route which is unique in WirelessHART is realized in the proposed algorithm. Especially, the need for broadcast routing is demonstrated and its realization is also presented in this paper. Secondly, after a careful analysis of the communication resource scheduling mechanism and its robustness requirements, a Graph route-based superframe scheduling scheme is proposed with its implement algorithm. The route-based superframe scheduling ideology in this paper is an extension of cross-layer design in the network management level. It is characterized to make a good combination of routing and superframe, then the network robustness can be significantly improved, and the latency of communication can also be effectively reduced. In addition, time slot conflicts and channel interference that may exist in network can be both avoided in the proposed algorithm. Thirdly, this paper made an in-depth study of the network maintenance tasks during the whole life of the network from its establishment to removement, and then the corresponding solution scheme is proposed. Among them, the network initialization and devices automatically join and leave is analyzed carefully, with a reasonable and simple solution proposed in this paper. To other maintenance tasks such as:network topology monitor, key updated and the design of network management superframe, solution scheme is proposed one by one, and then schedule all these tasks in the network management superframe with a reasonable order. To reduce the communication resources consumption of network maintenance, communication time slots are rationally shared by these tasks, through reasonable sequencing the delay of the task execution is significantly reduced. Finally, a simple network is taken as an example, to make a more intuitive description of the implementation process and results of the routing algorithms, superframe scheduling algorithm, as well as the network management and maintenance scheme that are proposed in this paper. |
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