Autonomous System for UHF RFID Signal Measurement in Industrial Environment

Abstract

Deployment of UHF RFID technology in the industrial environment is not easy to perform because of the heterogeneity of the environment, the propagation of the high frequency radio signal, the interference, and the associated timeconsuming implementation. The paper deals with deployment and evaluation of developed autonomous system for measurement of UHF RFID signals in industrial environment. Such a system allows, in defined 3D real-world locations, to obtain autonomously information about the actual Received Signal Strength Indicator of the moving RFID tag (Etalon) that is registered while investigated with each antenna of RFID reader. A corridor was chosen as an experimental area, and Received Signal Strength Indicator was evaluated by both, simulation and measurement methods. The results show a statistically significant relationship between measured and modeled Received Signal Strength Indicator in dBm at the 99% confidence level. The presented autonomous system can contribute to a more comprehensive analysis of measuring the electromagnetic field emitted by the UHF RFID antennas in various industrial environments.

Simulation of Radio Signal Propagation for UHF RFID Technology in an Indoor Environment Using Ray Tracing (Graphics) Method

“…RFID applications [1][2][3][4][5][6][7][8] Practical use RFID implementation [9][10][11][12] Difficulties of UHF RFID implementation Empirical methods [16,17] Inaccuracy is increased with specific forms of the environment (e.g., corridors) Deterministic methods [18][19][20]31] Computationally demanding depending on the number of walls and obstacles Ray tracing (physics) [15,[21][22][23][24][25][26][27][28][29][30]32,33] Calculation time increases with an increasing number of rays, inaccuracy in the calculation may occur due to the different number of incident rays Commercially available SW [21,22,[34][35][36][37] Some of the frequently used tools…”

“…In the simulation, the effect of reflections and refractions, where some parameters, such as the shape of the 3D environment and the influence of materials, are considered. The simulation results of this approach are compared with the results of simulations of the empirical Multi-Wall model used in the simulation tool I-Prop [11]. For the presented approach, we focus on verifying the functionality, repeatability, accuracy of the results and time consumption.…”

“…Furthermore, when designing the system, the parameters of the reader, antenna and tags must be taken into account, as well as the practical implementation (cable lengths, availability of electricity, etc.) [11]. Last but not least, other telecommunications technologies that can be operated in a given location in the same frequency spectrum should be considered to avoid undesired interference when designing an RFID system [11].…”

“…[11]. Last but not least, other telecommunications technologies that can be operated in a given location in the same frequency spectrum should be considered to avoid undesired interference when designing an RFID system [11].…”

“…From the physical measurements, we can mention, for instance, the determination of the required power (strength of the electromagnetic field) of the antennas of RFID readers by placing the tag in the space and measuring their detectability by the reader. The values of the RSSI (Received Signal Strength Indicator) parameter of the tag response at a constant power of the RFID reader can be recorded in order to determine the reading range of RFID UHF readers or antennas [11]. However, this procedure seems to be inappropriate in terms of time and money consumption.…”