Location identification using passive UHF RFID system

Abstract

Radio Frequency Identification (RFID) has been widely utilized and applied in retail stores and manufacturing environments. Over the years the advances in the technology provided the means for a wide range of intriguing applications, one of which is the location estimation of stationary objects. In a warehouse environment the identification of the stored items' locations in predefined shelves is of an essence. With hundreds or even thousands of stored items the tracking, locating, and retrieving one single item can be time consuming and costly, especially if the items are misplaced. A cost effective system is required to tag the stored items and automatically identify their locations. The system of choice was a passive ultra high frequency (UHF) RFID system utilizing very low cost tags, relatively long detection range and high rate of detection rate makes it most suitable for real time detection and tracking. In this paper the viability of the passive UHF RFID system to locate the position of a tagged objects, stored in a multiple shelved warehouse environment is investigated. A pilot system was implemented and its performance was investigated by a team of two students in the electronics engineering technology (EET) program during one semester senior design project. A 915 MHz RFID system performance was investigated and analyzed in a simulated environment in the radio frequency (RF) laboratory. The concept of using RFID system for position identification in the simulated storage environment was successfully proven. The pilot system was able to identify tagged items' locations with very high efficiency especially in an RF friendly environment. The work required the analysis of the RFID interrogator (reader) antenna and the passive RFID tags radiation patterns, and a methodical RF survey of the surrounding environment. It is emphasized that the senior design project has provided an excellant environment for the students to integrate all the knowledge gained during their educational period and apply it to implement a system utilizing a state of art technology in RF wireless communication. It provided a practical hands-on learning opportunity, and developed their ability to analyze and provide solutions for real world problems. The paper presents the experimental findings, their analysis, and the project educational outcomes. © 2011 American Society for Engineering Education.