RFID TECHNOLOGY -Location identification

Location identification

If a given reader is assigned to a known location, it is possible to track the current place of a given uniquely identifiable item. Numerous logistics companies and some postal services have already integrated such RFID-based features into their tracking services (several shipping and postal ser-vices, such as UPS, FedEx, USPS and Finland Post [8]; automatic vehicle location systems in pub-lic transport control in Vejle, Denmark [10]; location of rolling stock at the Swiss Federal Railways), and similarly, the physical location of work pieces is being kept track of in several manufacturing facilities, too (e.g.: in Dell’s facility in Xiamen, China [12]). The RFID tags to be read for localization can be either attached to containers or items, or they can identify the transporting vehicle itself. Aside from the benefit of providing exact information (as opposed to the risk of incomplete, delayed or corrupted data if entries are made manually), reading RFID tags does not require a long halt in the transportation process, making thus delivery more efficient. Also, farm animals can be effi-ciently localized using RFID tags while a similar tracking principle is applied in some prisons as well. Other location-specific application examples are envisaged using direction-selective readers. These aim to find the exact location of a tag in a wide area, such as golf balls on a golf course [9].

Transfer of further data

In the third application group, not only an identity is extracted from the tag but also auxiliary data are read or written. Data read from the tag usually contains information which would be difficult im-practical or impossible to obtain from a remote or pre-recorded database, or measurement results. Some products may provide instructions for proper handling this way (envisaged are cases where tags in food packaging would instruct an oven about the optimal cooking time [2], or tags in cloth-ing would select the right program for a washing machine [17]), while in a number of already im-plemented uses, tags provide medical measurement data e.g., about eye-ball pressure (sensor and transmitter integrated into artificial lens implant [6]). Writing data to a tag usually adds informa-tion about the processing of the given item (or delivery progress in transportation), and in a few cases, a new identity is assigned to the tag by rewriting (such as for reusable containers, pallets etc., as in a pilot project at the Finnish Post [8]). An interesting application is envisaged for washing machines where read-write tags in clothes also record how many times the given piece has been washed and select the proper washing program to adapt to aging of the fabric [17].

CONCLUSION

The paper gave an overview of the current state and trends of RFID technology. Even though nu-merous limitations and unresolved issues still hinder the widespread application of RFID, it can be already seen that especially enterprises in complex supply chains will benefit from RFID, once the application difficulties are overcome.