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A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats

Published April 2, 2019 by SAE International in United States
A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats
Sector:
Citation: Cuddihy, M. and Pottle, B., "A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats," SAE Int. J. Adv. & Curr. Prac. in Mobility 1(3):1028-1034, 2019, https://doi.org/10.4271/2019-01-0465.
Language: English

Abstract:

In this study, we present an intelligent and wireless subsystem for powering and communicating with three sets of seat belt buckle sensors that are each installed on removable and interchangeable automobile seating. As automobile intelligence systems advance, a logical step is for the driver’s dashboard to display seat belt buckle indicators for rear seating in addition to the front seating. The problem encountered is that removable and interchangeable automobile seating outfitted with wired power and data links are inherently less reliable than rigidly fixed seating, as there is a risk of damage to the detachable power and data connectors throughout end-user seating removal/re-installation cycles. The present study tackles this issue through outfitting three removable and interchangeable rear seat assemblies with resonant capacitive coupling wireless power transfer as to power each rear seat across a variable gap between the interior paneling and that side of the seat closest to the interior paneling. A fundamental design challenge this system presented was the need to develop a rugged method to account for different sizes of seating, and hence to accommodate variable wireless power gaps. This issue was addressed via use of impedance matching technology to present a nearly constant load impedance to the dc-to-radiofrequency power inverter. The wirelessly received power enabled additional electronics added to the rear seat assemblies to wirelessly communicate the seat belt buckle states to a central hub where it was displayed via a custom graphical interface. Our approach involved the visibly imperceptible integration of resonant capacitively-coupled transmitting and receiving antennae behind the interior paneling for the transmitter and underneath the outer fabric of the rear seating. The resulting subsystem demonstrated the ability to power both the seat belt buckle switches and wireless communication over a range of wireless power gaps.