Comprehensive Management System Of Streetlights Based On Wireless Sensor Networks

Streetlights are an indispensable part of urban infrastructure, and play an important role in the city traffic safety, public security, city landscape and people's living style. Today, most of the urban streetlights adopt manual modes, light-control, and clock-control, and most of the street facilities adopt the management mode of spot inspection. Disadvantages of these traditional control and management modes of streetlights are easily leading to energy waste, and untimely fault detection. With the rapid development of wireless sensor networks, information, communication and automation technology, a comprehensive management system of streetlights based on wireless sensor networks is researched and developed in this thesis.In this thesis, the structure of urban streetlights management system is studied; the weaknesses and deficiencies of the traditional streetlights management modes are analyzed. The application status of the wireless sensor networks, the system structure, network deployment, neighbor discovery and routing protocols of the wireless sensor networks and the working performance of CC2500 nodes are studied. Based on wireless sensor networks, a comprehensive management system of streetlights is designed. The hardware/software of the streetlight node control and the sink node control are designed. The program of network communication protocol is coded. Finally, the performance of the nodes, the wireless sensor networks and the energy-saving effect of the system are tested and evaluated.For maintaining position information in the streetlights'comprehensive management, a method of nodes/streetlights positioning is proposed that is named as Single Point Positioning Method. Algorithm of automatically obtaining addresses is adopted to get the long address of nodes randomly, and the mapping table is established based on positioning information. The network nodes physical location is well established by the regular distribution of short address.According to "strip with two paralleled lines" mesh topology of the streetlights system, a routing algorithm based on local information Improved Foolproof Routing Algorithm II is put forward. Adopting the strategy of maintaining Received Signal Strength Indication (RSSI) of neighbor nodes, a dynamic routing algorithm is designed based on the Signal Strength Index (RSSI_dBm).The test results show that the system has the following characteristics. Firstly, the implementation of green lighting is achieved, which includes:(1) the single streetlight control (2) a variety of switch-modes of 1/2,1/3, etc., and (3) mode of lighting according to the need of time, sections and scenarios. Secondly, under baud rate at 2.4kbps, transmitted power at+1dBm,38 nodes in the network, the network deployment time is less than 380s, and the response time of the farthest node is 7s-11s when the Improved Foolproof Routing AlgorithmⅡis used. The network performance meets the project requirements. Thirdly, the system has many merits, such as low cost, easy expansion, no need of wiring and easy maintenance. Fourthly, about 35 percent energy saving is realized. Therefore, the system is suitable for the comprehensive management of streetlights, especially for the solar streetlights system.