1 research outputs found
Chipless RFID sensor systems for structural health monitoring
Ph. D. ThesisDefects in metallic structures such as crack and corrosion are major sources of catastrophic
failures, and thus monitoring them is a crucial issue. As periodic inspection using the nondestructive testing and evaluation (NDT&E) techniques is slow, costly, limited in range, and
cumbersome, novel methods for in-situ structural health monitoring (SHM) are required.
Chipless radio frequency identification (RFID) is an emerging and attractive technology to
implement the internet of things (IoT) based SHM. Chipless RFID sensors are not only wireless,
passive, and low-cost as the chipped RFID counterpart, but also printable, durable, and allow
for multi-parameter sensing.
This thesis proposes the design and development of chipless RFID sensor systems for SHM,
particularly for defect detection and characterization in metallic structures. Through simulation
studies and experimental validations, novel metal-mountable chipless RFID sensors are
demonstrated with different reader configurations and methods for feature extraction, selection,
and fusion. The first contribution of this thesis is the design of a chipless RFID sensor for crack
detection and characterization based on the circular microstrip patch antenna (CMPA). The
sensor provides a 4-bit ID and a capability of indicating crack width and orientation
simultaneously using the resonance frequency shift. The second contribution is a chipless RFID
sensor designed based on the frequency selective surface (FSS) and feature fusion for corrosion
characterization. The FSS-based sensor generates multiple resonance frequency features that
can reveal corrosion progression, while feature fusion is applied to enhance the sensitivity and
reliability of the sensor. The third contribution deals with robust detection and characterization
of crack and corrosion in a realistic environment using a portable reader. A multi-resonance
chipless RFID sensor is proposed along with the implementation of a portable reader using an
ultra-wideband (UWB) radar module. Feature extraction and selection using principal
component analysis (PCA) is employed for multi-parameter evaluation.
Overall, chipless RFID sensors are small, low-profile, and can be used to quantify and
characterize surface crack and corrosion undercoating. Furthermore, the multi-resonance
characteristics of chipless RFID sensors are useful for integrating ID encoding and sensing
functionalities, enhancing the sensor performance, as well as for performing multi-parameter
analysis of defects. The demonstrated system using a portable reader shows the capability of
defects characterization from a 15-cm distance. Hence, chipless RFID sensor systems have
great potential to be an alternative sensing method for in-situ SHM.Indonesia Endowment Fund for Education
(LPDP