Towards Localization and Tracking of Wind-Dispersal Small-Scale Coded
Fliers Based on Passive RFID Infrastructure
Abstract
The concept of sensing environmental parameters in the air has been
raised recently by utilizing drone-based, insect-based, or
wind-dispersal-based mechanisms using different system infrastructures.
Interestingly, wind-dispersal mechanisms use no driving mechanical
system and can be dispersed only by the wind power to scan and sense
selected areas of interest. Additionally, Ultra High Frequency (UHF)
passive Radio Frequency IDentification (RFID) technology is considered
with a low-cost infrastructure and high coding capacity of 96 bits in
which RFID tags operate without the need for a battery. In this paper,
we propose a system of wind-dispersal fliers which are coded and
localized based on passive UHF RFID technology toward sensing
environmental parameters (e.g. temperature) at a specific position in
space. For the flier’s mechanical design, a 2D structure is first
designed, inspired by winged seeds, that consists of four wings with
asymmetrical cross-sections between them in order to provide better
mechanical stability during descent and more integration solutions with
UHF RFID tags. The 2D structure is then transformed into 3D
configurations by tilting the blades at different angles and utilizing
different curvatures. By introducing porosity in the 3D design and
optimizing the blades’ angles and curvature, a low terminal velocity of
1.64 m/s is achieved based on measurements. The fliers are fabricated
using Laser Sintering from Polyamide 12 (PA12) which has a low weight
and good mechanical properties with a low thickness of 200 μm. For
system demonstration toward reliable identification, localization, and
tracking of fliers during falling, distributed reader antennas are used
to interrogate a coded flier equipped with a passive RFID tag that uses
a UHF Gen2 chip. Received Signal Strength Indicator (RSSI) based
localization is used with an adaptive trilateration algorithm to tackle
environmental impairments. The averaged measured location error achieved
based on the proposed system is approximately 8.5 cm.