UHF RFID Tag Antenna-Based Sensing for Corrosion Detection & Characterization Using Principal Component Analysis

Abstract

Recently, structural health monitoring (SHM) using radio frequency identification (RFID) tag antenna-based sensing (TABS) has received increasing attention because of its wireless, passive, and low-cost characteristics. However, a great challenge in the SHM using RFID TABS is multiple influences in the measurement. This paper presents an ultrahigh frequency RFID sensor system for corrosion detection and characterization. In this paper, a 3-D antenna sensor is designed to work on the surface of a protective coated steel sample. Sweep-frequency measurements are applied for analog identifier with principal component analysis (PCA) to overcome the multiple influences from reader-tag orientation, distance, and environment. Feature extraction and selection though PCA can get robust and sensitive defect information by projecting the test data into an orthogonal feature space. The test results demonstrate that the proposed method can be applied to detect and characterize early-stage corrosion in metals.

Feature Extraction for Robust Crack Monitoring Using Passive Wireless RFID Antenna Sensors

“…The possible types of interference for measurement include system configurations such as circuit bandwidth and communication distance, sample influences such as surface roughness or sample geometry, thickness, permittivity, and permeability, and environmental conditions such as operating temperature [24]. In a real environment, the defect and interference will behave as a combination of multiple types.…”

Passive UHF RFID Tag as a Sensor for Crack Depths

“…RFID system is classified into three groups due to operating frequency, low-frequency LF, high-frequency HF, and ultrahigh frequency UHF. Later UHF RFID is the most popular used when it is compared with LF and HF RFID systems because of its far distance reading range up to ten meters [3], and it could be deployed to form a monitoring WSNs. The disadvantage of using UHF RFID signals it cannot penetrate to detect defect inside material while other frequency ranges of RFID were used for that purpose [4].…”

“…The direct strategy may include tag turn on power [5], backscattered power [6], and phase [7]. The indirect strategy may include radar cross section (RCS) [8], an analog identifier (AID) [3], and an inphase/quadrature IQ signal based sensing [4]. The indirect measurement strategy may need additional hardware for investigation or need more information about the tag antenna specifications like antenna impedance, chip impedance, and chip activation power.…”

“…Commercial tags unavailable information's and the limitation of the harvested power level and the attenuation of the transmitted signal make the use of a passive antenna for defect detection remains a challenge. However, regarding the use of the passive tag, researchers are developing various techniques for defect detection like strain [9][10] [11], cracks [6][12] [13], and corrosion [3][14] [15]. The limitation of the techniques used for crack detection either it used short communication range like LF or HF, nor it can detect the cracks that directly persist on tag antenna instead of the cracks that occur in the monitored substances.…”

“…The contribution of the proposed article can be drawn from its ability to detect the under tag crack depth by using UHF reader platform, while most of the similar research focus on designing tags for sensing [3], or they may use high-cost apparatus such as vector network analyzer (VNA) [14].…”