Study on Influences Analysis of RFID and Application in Midget Coil Warehouse

In steel coil warehouses management system, the steel coil information is updated by the RFID-based coil identification. There are two challenges of WMS adopted to small scale coil-based steel logistics enterprises. One is that it is hard to locate a steel coil in the nonstandard warehouse space. The other is that the shielding of plate metals influences the identification rate of RFID tags attached to the coil. In order to cope these problems, a coordinate system should be established for location, and the identification performance due to neighboring metallic objects must be improved for steel coil identification. In this paper, we present a improved RFID method, named Nonstandard warehouse Location and Identification method(NLI) for those midget steel coil warehouses with nonstandard freight spaces, which is aiming at their characteristics such as metallic environment, stockpile method of coil, management methods, etc. First, we convert the nonstandard space to be standard by the establishment of coordinate system, so that steel coils can be located with position RFID tags. Second, an effective tag attachment and reader fixing method helps identifying the article information. The position and article information of coils are separated by means of building a coordinate system within the irregular freight spaces, so that the problem of identification and location of coils is solved with less cost. This method has been adopted in a steel logistics company. In the application, the coils location accuracy rate keeps 100% during crane operation with a moving speed less than 22m/min. The coils information identification accuracy rate achieves 100% with no more than 3 coils lying side by side.