Based On The ZigBee Protocol Wireless Sensor Network Localization Algorithm And Design

In recent years,wireless technology and sensor technology has been an unprecedented development,For people's increasingly demand for related technology,a new wireless sensor network technology turned out.The technology is widely used in military,industrial,agricultural,animal husbandry,intelligent home,intelligent city and other fields by adopting the characteristics of low cost,small size and easy deployment of sensor nodes.Although these applications cover all walks of life and have their own characteristics,they have one thing in common,that is,the location information of the sensor nodes is required.If the location of the sensor node is missing,then the system to obtain all the information has lost its meaning.So the way to obtain node location information is particularly important.For a long time,the sensor position information is obtained through the GPS positioning device to complete.We know that the application of GPS devices needs to consume a lot of money,which does not meet our low demand for WSNs.Therefore,how to control the cost of sensor nodes may be positioned is a hot topic.Many R & D institutions are committed to the development of a new sensor node location algorithm acquisition technology,currently rely on the wireless sensor network itself to locate the senor node is the most popular way.The special feature of this technology is that only the use of communication between nodes,to take a special algorithm to determine the location of the node to complete the positioning.This paper introduces the related concepts of sensor network location technology,several positioning algorithms and development status,and analyzes the existing problems of the technology and puts forward the improvement scheme.(1)In the traditional wireless sensor positioning system,the positioning of the target node(tag node)often needs to be realized by means of a large number of auxiliary positioning nodes(anchor nodes).However,the location information of the anchor node is obtained in two ways,that is,it is obtained by GPS positioning device or manual measurement,and the disadvantage of these two methods is that the cost is too high and the positioning accuracy is greatly affected by the artificial influence.Meanwhile,when the system is in an indoor environment,the GPS positioning accuracy greatly decreased,and therefore may appear unable to locate the case,this is the problem currently facing.In order to solve this problem,this paper designs an anchor node self-localization algorithm.The core of the algorithm is that the information known and available by the integrated system is used to locate the unknown anchor nodes,where the system known information is the location information known to the partial anchor nodes,the available information is the information arrival time information and the angle information.Thereby greatly reducing the number of anchor nodes known information system needs an initial position,the positioning accuracy of the system under the influence of a small case,reducing the system cost,improve the system scope.(2)Sensor node NLOS communication.When the wireless sensor network is used in the indoor environment,there will often be a kind of problem,that is,the transmission of information between the sensors nodes will be obstructed obstruction,resulting in the system cannot be LOS communication.The direct consequence of this kind of problem is that we can get the information obtained through the positioning system is not accurate and affect the final positioning accuracy.For this kind of problem,this paper proposes a NLOS identification algorithm.The NLOS distance is used to identify the node with NLOS communication from the node,and it is eliminated at the time of positioning to reduce the NLOS communication problem.(3)Based on the arrival time difference of the positioning algorithm is high complexity and system power consumption is too high.Using the traditional TDOA positioning algorithm for positioning,will encounter the positioning equation over the non-linear problem,this time need to use the iterative method to solve.The use of iterative method,in addition to improving the complexity of the algorithm,but also increase the system power consumption.Based on this,this paper proposes a hybrid algorithm of TDOA and AOA.Combined with TDOA and AOA information,the problem of solving the iterative localization equation is transformed into solving the quadratic equation,which greatly reduces the complexity of the algorithm and the power consumption of the system.The number of anchor nodes required to locate.Meanwhile,for the problem of high power consumption of the system,the paper also uses the Zigbee protocol instead of the Wi-Fi protocol.This reduces the cost of the system,increased system life.Through the simulation analysis and the realization of the final system,the validity of the algorithm is proved,and the correctness of the idea is proved.