Research On The Key Technology Of 3-D Location Of Storage Dangerous Goods Based On Wireless Sensor Networks

With the rapid development of science and technology,the quantity and type of dangerous goods and materials are more and more.The dangerous goods has the characteristic of instability which is inflammable explosive,poisonous,corrosive and radioactive.Once accident occurs,the aftermath could be very serious.It will have bad influence on people's health,public safety,economic development and eco-environment.Realizing the real time supervision of dangerous goods' condition and position in the process of production and transport,to timely alert and reduce the occurrence of accident with sensor technology have important theoretical significance,huge economic value and far-reaching social benefits.Compared with the two-dimensional positioning system,the three-dimensional localization algorithm extends the application space of the positioning system,and can provide a more accurate physical position and has a wide application prospect.Based on the extensive study of a large number of references,a three-dimensional positioning system for storage dangerous goods based on wireless sensor networks was designed and fabricated,which can achieve the three-dimensional real-time positioning of dangerous goods and broad the scope of dangerous goods monitoring information to improve the reliability of dangerous goods monitoring.With the research of the distance measurement algorithm combined with the received signal strength indicator(RSSI)and centroid algorithm,a three-dimensional localization algorithm based on adaptive iterative search is proposed.Using Min-Max algorithm to automatically adjust the initial search step,through several iterations,update the search point and search step to improve the positioning accuracy of the node.Using Matlab software to establish communication model according to the actual environment,which improves the reliability of simulation results.The simulation results show that the improved algorithm obviously improves the positioning accuracy and has good stability.The advantages,architecture,work characteristics of 6LoWPAN communication protocol are studied deeply.Based on the advantages of 6LoWPAN protocol can realize the connectivity between wireless sensor network and Internet,a three-dimensional positioning system of wireless sensor network is designed.The system is established with several micro nodes,which are based on RF chip AT86RF231 and Contiki operating system.The positioning system has high positioning accuracy with the features that has simple structure,small size,easy to install and extend the function.It is not only for dangerous goods monitoring,but also for other logistics warehousing monitoring.The corridor of the laboratory building is selected as the experiment environment to measure the relevant parameters of the communication model.And a PC software is composed with VS2010 and Matlab2010 to calculate and display the positioning results.Beacon nodes are installed in the environment to verify and test the positioning effect.