Research Of Personnel Positioning And System Implementation For Wireless Sensor Network

Wireless sensor network is an advanced and hot research area which is formed by many crossed subjects. It contains many advanced technologies such as wireless communication, sensor, modern network, embedded computing and so on. It’s an awfully new platform which can obtain the information. Because of its self-organization, flexible deployment, low cost, low power consumption and high fault tolerance etc, so wireless sensor network is widely used in military, health care, intelligent traffic control, environment monitoring, building monitoring, intelligent greenhouse, intelligent home furnishing and many other fields, it is highly concerned in the world.Positioning is one of the key supporting technologies of wireless sensor network, for most application in wireless sensor network, apperceived data is useless without location information, so location information is particularly important for monitoring activities in wireless sensor network. The positioning of the node itself is the premise to provide monitoring event location information, so precise positioning of the sensor nodes is one of the most basic function of wireless sensor network, it plays an important role in a variety of applications. This thesis mainly studies the positioning in wireless sensor network.The thesis firstly introduced the research background of the subject, and reviewed the development of wireless sensor network and its current research status in positioning, secondly, introduced the ZigBee technology in the wireless sensor network and related basic knowledge, focused on the analysis of the hierarchical structure of ZigBee protocol stack, then studied the localization technology in wireless sensor network in depth, the typical localization algorithms were classified and compared, focused on the localization algorithm based on RSSI, analyzed RSSI ranging model and error in depth, and a method of distance correction was proposed. Using RSSI technology to measure distance, and corrected the measuring distance by using the principle of least square method, combing an optimized weighted centroid algorithm, through the Matlab simulation, the results showed that the positioning accuracy was improved by the improved algorithm. Next, studied and designed the whole system. In the design of system hardware, designed each network node in the positioning system by using chip CC2430, introduced the circuit design in details, like power, radio frequency, serial communication, debug interface, reset and so on. And in the design of system software, analyzed and studied the communication mechanism and work process among each node in depth, on the software platform IAR, according to the communication protocol of ZigBee protocol stack, designed the programs for different nodes to accomplish corresponding functions of each node, and developed the PC detection software through VC++6.0to achieve real time monitoring of the node in the positioning area. Last, debugged and tested the entire positioning system, the results showed that the system with the positioning algorithm proposed by this thesis achieved a good positioning effect without additional hardware, and the cost was decreased. It has certain practical value.