Abstract: Combining ZigBee technology with Radio Frequency Identification (RFID) technology to build a network of RFID handheld readers based on ZigBee technology. The RFID handheld reader network is connected by means of self-organizing network, which improves the flexibility of the original RFID, and changes the original network from a single-hop network to a multi-hop network, increasing the read/write distance of the original RFID, and The sensor is embedded in the active RFID tag, allowing the reader to read both the item information and the surrounding environment of the item.
Radio Frequency Identification (Radio Frequency IdenTIficaTIon, RFID) is a non-contact automatic identification technology realized by wireless communication technology. It has the characteristics of non-contact, high security, fast transmission speed and multi-target recognition. With the development of VLSI technology, the cost of RFID devices has been greatly reduced, and RFID technology has gradually become practical and has been widely used in many fields. The RFID reading distance is long, the data can be written and accessed, and the content of the label can be dynamically changed; multiple tags can be processed at the same time; the data access of the tag is password protected, and the security is higher; the object attached to the RFID tag can be attached Track and locate. The RFID system consists of two main parts: a tag and a reader. Electronic tags have successfully solved the problem of passive and contactless, and are a breakthrough in the field of electronic devices. The tag consists of a coupling element and a chip. Each tag has a unique electronic code, which is attached to the object to identify the target object and object information. It can also store additional information such as the product name and product type. According to different electronic power supply methods, it is divided into active electronic tags and passive electronic tags. When the passive electronic tag is within the read range of the reader, the electronic tag extracts the power required for its operation from the RF energy emitted by the reader. The working power supply of the active electronic tag is completely supplied by the internal battery, and the energy supply of the tag battery is also partially converted into the radio frequency energy required for the electronic tag to communicate with the reader, thereby transmitting the data in the tag or receiving the data of the reader. This information is then transmitted to the background application system for processing.
ZigBee technology is a short-range, low-complexity, low-power, low-data-rate, low-cost two-way wireless communication technology. It is mainly suitable for sub-automatic control and remote control. It can be embedded in various devices and supports geolocation. ZigBee technology will be the lowest power and cost technology compared to existing wireless communication technologies. ZigBee technology is not a completely unique and new standard. Its physical layer, MAC layer and link layer adopt IEEE802.15.4 (Wireless Personal Area Network) protocol standard, but on this basis, it has been improved and expanded. ZigBee is a star-shaped, patch-like or mesh network based on independent working nodes, so each node has the same function. It is divided into reduced function devices and full-feature devices: In networking communication, it is only a subset of its functions; in addition, some nodes are called full-featured devices (also called coordinators), which are responsible for communicating with the controlled child nodes, pooling data and issuing control, or Play a role in communication routing.
RFID has poor anti-interference and is susceptible to external environment, and the effective reading distance is generally short, especially in the case of metal and water interference. Even with the active RFID tag with internal battery, the tag can actively transmit signals, and can identify multiple targets at the same time. The recognition distance of the active tag is adjustable (usually 1~30m), but the distance is still limited; you can connect it Into the wired network, but the wired network needs wiring, can not be connected anytime, anywhere, the installation is not convenient. These applications for RFID are a huge limitation. In this paper, a handheld reader is used. A wireless network is required between RFID handheld readers to realize wireless communication. The ZigBee protocol has obvious advantages. Therefore, in designing schemes, IEEE802.15.4 standard and ZigBee protocol are the preferred protocol standards. , using the 2.4 GHz global common frequency band. This paper combines ZigBee and RFID to build a RFID network based on ZigBee technology. Using the effective radius of up to 100m, the expansion of RFID read/write range will have extremely broad application prospects [1]. Therefore, the RFID technology is extended from the information mode of collecting simple nodes to the application of self-organizing network and cooperative operation in the wireless personal area network, which can track and locate the items and monitor the environment around the items in the wireless state. Counting items, etc., provides a strong technical guarantee for the ultimate realization of the "Internet of Things."
1 Feasibility and networking advantages of RFID and ZigBee technology integration
In the RFID-related protocol, only the communication air is 1:3, and ZigBee has a relatively complete communication networking protocol. In the working frequency band, ZigBee can choose to work in the 2.4GHz ISM band (the global frequency band is conducive to expansion), while RFID can work in 915MHz or other frequency bands, so the two can not interfere with each other at the communication frequency. The ZigBee module can penetrate obstacles of a certain thickness during work, without the limitation of line of sight, and RFID is limited by obstacles, and the two can complement each other. Through the self-organizing network protocol, each device in the network can directly communicate wirelessly or connect to other devices through network forwarding, which saves a large number of wired device connections, and the network reliability and frequency utilization rate are very high. And ZigBee has a relatively complete security authentication mode.
ZigBee technology is used to network RFID readers. Compared with traditional reader networks, ZigBee technology has the following advantages: First, wireless networks do not need wiring, and installation is convenient; Second, wireless networks are more flexible than wired networks, and can be based on The specific situation connects the RFID to the network anytime and anywhere; the third is that the wireless network management is easy and can be set by software; the fourth is that the network reconstruction is fast, and the network expansion is simple, once a node has a problem. New RFID readers can be added to the network anytime, anywhere by transmitting data through other nodes.
2 RFID system network construction method based on ZigBee technology
First, the active electronic tag in RFID is combined with the sensor. The sensor generally does not care about the information of the item. It focuses on the environment surrounding the identified object, such as temperature and humidity, pH value, blood pressure value, and the like. The information is read by the RFID reader and the reader can form a network when needed in the application. The sensor can acquire the data of the physical world, and can concentrate the main energy of the network on the data. When it is necessary to specifically consider the information of a specific node, the RFID bridges the physical world and the information world, and the sensor is embedded here. By combining the two in an electronic tag, the physical world can be well integrated with the existing information world, fundamentally changing the existing IT system. All this laid a good foundation for new applications.
Using the active tag and sensor integration to form the super tag principle (Figure 1), sensors with different functions are embedded in the tag, each sensor will independently and periodically collect data, and then become the original data after A/D conversion. The microprocessor processes the raw data before it is read by the reader. This super tag can sense environmental information around the tagged object, such as temperature, humidity, pH, blood pressure, etc. When the reader reads the information in the super tag, the reader will read the information together.
Figure 1 super label principle
After adopting active RFID, the tag has a battery inside and actively transmits signals, and the handheld reader can not actively transmit power and recognize multiple targets at the same time. The system's super tag consisting of active tags and sensors periodically transmits data processed by the microprocessor, and the reader reads the data in the super tag within the read range. The reader processes the information in the tag and then transmits the information to the computer (Figure 2).
Figure 2 RFID system
The traditional RFID network is a single-hop network and contains a large number of tags and multiple handheld readers in this area. When RFID and ZigBee are combined, a multi-hop network can be formed, so that readers can communicate with each other. The ZigBee module is embedded in each RFID reader, and the readers are connected in a self-organizing network to construct an RFID reader network, which enables efficient and fast reading of information on the label and simplifies the networking process. The tag data collected on each RFID reader can be quickly transferred to the control computer, and the RFID tag reader can exchange the collected tag information in real time, which can expand more new applications. As shown in FIG. 3, a ZigBee module is embedded in each RFID reader to reach a wireless connection network between multiple readers, and communicate with each other to exchange contents in the super tag, thereby increasing the read/write distance and realizing The purpose of multipoint wireless acquisition and transmission of data. Since each handheld device is mobile, the contact between them will change, the structure of the network will change at any time, and the communication objects must be re-find between the modules to refresh the original network, so a self-organizing network is adopted. The AODVjr routing protocol is used at the network layer. The vector path selects energy-based factors, has the characteristics of fast adaptation to the dynamic link environment, low processing and memory overhead, and support for multicast. The routing algorithm has the ability to learn and discover the topology autonomously and can be automatically repaired. Each mobile terminal in this network is a full-featured device with routing capabilities that communicate with the coordinator. Finally, an RFID recognition system based on ZigBee technology for multi-point automatic identification and intelligent wireless networking is formed. This network has two characteristics: one is that the RFID reader can move data collection, and the other is that the entire formed network can move.
Figure 3 RFID and ZigBee network
3 Conclusion
Due to the poor anti-interference of RFID, the external environment is easy to be affected, and the effective reading distance is short, we combine ZigBee and RFID technology to build a network of RFID systems based on ZigBee technology, and embed the sensor. Go to the label. This system expands the range of reading and writing of RFID, and can identify the items as well as the information of the environment around the items, laying the foundation for tracking and monitoring the condition of the items. The synergistic application of these technologies can provide a strong technical guarantee for the ultimate realization of the "Internet of Things."
Description for Wire Sleeves Electrical Cable For Electronics And Automobile
With excellent flexibility, flame resistance, wear resistance and heat insulation.
Strong corrosion resistance and abrasion resistance.
Excellent softness, easy to bend.
Durable in use.
Can be used for wire and cable protection, pipe and hose, indoor wiring etc.
It offers durable abrasion resistance in a wide range of industrial applications.
The open weave construction allows an easy installation on a bundle of hoses and cables, even if some with bulky or large connectors.
Totally expanded the sleeving can reach at least one point five times than the initial dimension.
Features of Pet Expandable Braided Sleeve
Expandable Braided Sleeves is ideal for a limitless number of electronic, automotive, marine and industrial wire management and bundling applications. Examples include engine compartment dress up, home theater wire management, customizing computer case wiring, office wire management, automotive harnesses, scuba hose protection, and many more. Threads of different colors and textures could be braided into different patterns. Each of our products is tailored to the client's business and needs.
PET polyester Expandable Braided Sleeving is flame-retardant and halogen-free. Braided sleeve offers durable abrasion resistance in a wide range of industrial applications. The open weave construction allows an easy installation on a bundle of hoses and cables, even if some with bulky or large connectors.
Totally expanded the sleeving can reach at least one point five times than the initial dimension.
Wire Sleeves Electrical
Braided Cable Sheath,Wire Sleeves Electrical,Cable Sleeves Harness,Pet Expandable Braided Sleeve
Shenzhen Huiyunhai Tech.Co.,Ltd , https://www.hyhbraidedsleeve.com