RFID is an emerging technology. Especially based on a 900 MHZ UHFEPC Gen2 standard, RFID would influence and change people’ life style in the next few years. With the traditional automatic identification technology, suchas bar code, magnetic recording, IC card technology, UHF RFID has the following unique advantage: reading a long distance, fast reading and writing, highefficiency. Compared with other technology of RFID, its cost is much lower.This makes the UHF RFID technology increasingly favored by people, and emerge in many new applications.
UHF RFID vehicles management is based on RFID technology. UHF tag reading can be as far as 3 to 6 meters. Which is suitable for reading inward and outward or key points. And with the management system and GIS geographic information system, we can track the vehicle moving and positioning.
In the existing RFID passive application and wireless environment,there are three ways of solving the issues of moving point positioning and vehicle tracking. They are respective: using on-board RFID reader todo landmark tracking; Using vehicle tags for key points records; And tracking WiFi on the way according to the pure (RFID), wireless network and mobile computer.
Now we will introduce three ways of application principle as follows:
Firstly, landmark automatic readuhf long distance rfid reader fortracking
Landmark label adopts the RFID reader for identification, when vehicles pass, the RFID Reader can which can identify the RFID reader .RFID reader can identify landmarks within 1.5 meters distance. Label content via the wireless network is passed to the background management system, the location point can reflect by GIS geographic information system on the monitor screen, so as to realize the vehicle tracking and positioning.
Programs, landmark tags and readers vehicles must be defined through rigorous coding.
Landmarks label must be unique: each represents a landmark position, which must be unique in the GIS information systems.Landmarks can express only one position, but does not indicate the direction of vehicle operation.
Vehicle identification reader:Car readers also need a unique identifier, that is, when the reader reads the RFID data, the data along with the machine's serial number must pass along the information to the network, after analysis reflected on the monitor screen by the GIS with a form of vehicle movement points.
Wi-Fi: In order to achieve real-time reliable delivery of datacollection, the venue must build a wireless communications network.
Second,use the vehicle label to record key point
The key point means to use channel-point of stationary reader device, when the vehicle passes, the stationary reader device will obtain car tag information,and pass the data to the GIS system, after the adoption of software analysis, It will get the vehicle moving information. The key points are usually set up in some doorway, or at the junction of the channel mouth to be used to provide the path of the vehicle mark.
Vehicles need to install the RFID tags, which represents the unique information of the vehicle. When car labels pass through adoor or passage, stationary reader can identify the tag in the range of 3-6meters to determine the position of the vehicle.
Automotive tag applications: Car label must bemetal label, and has some strength to use for the truck environment. Label onthe side of the vehicle, so that the reverse sides of the reader antenna near the door or passage can read. By identification of the antenna, it is possible todetermine the route of travel of the vehicle, without the need to get throughthe software analysis.
Landmarks refer to UHF RFID tags which are buried in the ground, and can be read by device. Once landmarks label buried, it is noteasy to replace, therefore, the best solution of landmark label is to use passive tags, UHF Gen2 tags can better adapt to the landmark application.
Door passage Reader: the channel of the door is used with XR440 fixed readers and high-performance reading antenna, the antenna is set up on both sides of the channel. Each reading antenna has a different identity, which can support back-office systems to analyze aspects of the vehicle position and travelling.
Program requires no the wireless network, the stationary reader can be connected directly to the system via a wired network
Third, wireless networks and mobile computers locate WiFi
WiFi positioning mode locates the position of a mobile device with signal level provided by the venue in the wireless network . Besides, the mobile device must have WiFi communication module.
The principle of WiFi positioning is the use of three-point positioning methods, namely the exchange of mobile devices via a wireless signal and three wireless network access point to identify the location of a mobile device, because the distance of the mobile device to the three different wireless access points is different, so the wireless signal field reflected inthe wireless access point of the mobile device will vary. With algorithm,can we determine the precise location of the vehicle .
Requirements for wireless networks: WiFi positioning usually havehigh demands on the wireless network , the denser the network of access points,the higher positioning accuracy is.
Mobile computer requirements: a mobile computer must have a WiFi wireless network communications capability.
Analysis System: WiFi positioning analysis system is a third-partysoftware system, it must provide space-based AutoCAD drawing to run the analysis system, and before the application,there is a need for professional field testSite Survey, to determine the mark point information .
Identifying the landmarkpoint is intended to determine the conditions in the field, this information isapplied to the wireless signal in the region. When the mark point information value measurement is completed, the mobile computer move nearby, it will serveas the field strength information analysis by management software, to comparethe reference point value.
The accuracy of WiFi positioning is about 0.5 m under the conditionsof the wireless network, to meet the requirements.
TAG:   Outdoor RFID  UHF RFID vehicles management