Optimal location of RFID reader antennas in a three dimensional space

Radio frequency identification (RFID) is a technology most commonly used for the tracking and identification of objects. Optimally implementing RFID is challenging, especially in supply chain management where the use of passive tags is more common. Challenges in RFID implementation include, costs, standardization, privacy, performance, reliability and a need for greater collaboration. Systems integration will be expensive too in most current systems. Due to the nature of RF communications, many RFID systems involve multiple readers. Therefore, determining the number and position of reader antennas has a significant effect on success of the deployment. In this paper, we propose two optimization models and a GRASP metaheuristic that consider the effect of the orientation of antennas, the type of material to identify, and the interference from obstacles in a three-dimensional warehouse. The solution gives the minimal number of readers along with their positions for 100 % coverage of the tagged items.