Brendan O’Flynn

The DSYS25 sensor platform

In this demonstration, a new sensor platform named DSYS25 is presented. The platform has a unique hardware design and runs a customized version of the TinyOS operating system. Transceiver hardware and packaging distinguish the D-Systems platform from other available designs.

Power management for sub-mW energy harvester with adaptive hybrid energy storage

Energy harvesting with its ubiquitous availability is intensively investigated to extend the wireless sensor nodes lifetime. While the harvested power is often less than 1 mW, the commercial-off-the-shelf power management circuits designed for conventional battery applications operate in much higher power. A designated power management module for sub-mW energy harvester is proposed in this article to increase the energy conversion efficiency and extend the energy storage lifetime for small input power. The proposed module consists of discrete component–based pulse-width modulation (PWM) controlled synchronous boost converter structured impedance matching circuit and supercapacitor/micro-battery hybrid energy storage. The synchronous boost converter-based power management circuit achieves 79% conversion efficiency at the input power of 0.5 mW. The power loss during the energy conversion is significantly reduced and thus allows wireless sensor nodes to be powered from a minimum of 120 Lux fluorescent light with a photovoltaic cell smaller than a credit card. The supercapacitor/micro-battery energy storage provides lifetime of more than 73 h when no external energy is available. The experimental results with 25 energy harvester–powered wireless sensor nodes demonstrate that the practical ultra-low–power design makes sub-1-mW energy harvester power management applicable.

Celeritas — A Wearable Sensor System for Interactive Digital Dance Theatre

Celeritas is an artistic/scientific collaboration between the Tyndall National Institute (Cork), the Interaction Design Centre in Limerick, Cindy Cummings (Dance Artist, Cork) and Todd Winkler (Composer and Digital Artist, Brown University, USA). Research Teams at the Tyndall Institute are developing wireless sensor network nodes, also known as motes, and associated miniaturized sensors. Motes can be applied in many different domains, ranging from medical and environmental monitoring to everyday applications in ubiquitous computing. This project aims to apply Tyndall’s sensor system to create a wireless dance costume for audio/visual performance using inertial sensor monitoring technology.

Hand Tracking and Gesture Recognition Using Lensless Smart Sensors

The Lensless Smart Sensor (LSS) developed by Rambus, Inc. is a low-power, low-cost visual sensing technology that captures information-rich optical data in a tiny form factor using a novel approach to optical sensing. The spiral gratings of LSS diffractive grating, coupled with sophisticated computational algorithms, allow point tracking down to millimeter-level accuracy. This work is focused on developing novel algorithms for the detection of multiple points and thereby enabling hand tracking and gesture recognition using the LSS. The algorithms are formulated based on geometrical and mathematical constraints around the placement of infrared light-emitting diodes (LEDs) on the hand. The developed techniques dynamically adapt the recognition and orientation of the hand and associated gestures. A detailed accuracy analysis for both hand tracking and gesture classification as a function of LED positions is conducted to validate the performance of the system. Our results indicate that the technology is a promising approach, as the current state-of-the-art focuses on human motion tracking that requires highly complex and expensive systems. A wearable, low-power, low-cost system could make a significant impact in this field, as it does not require complex hardware or additional sensors on the tracked segments.

Energy-Aware Dynamic Route Management for THAWS

In this research we focus on the Tyndall 25mm and 10mm nodes energy-aware topology management to extend sensor network lifespan and optimise node power consumption. The two tiered Tyndall Heterogeneous Automated Wireless Sensors (THAWS) tool is used to quickly create and configure application-specific sensor networks. To this end, we propose to implement a distributed route discovery algorithm and a practical energy-aware reaction model on the 25mm nodes. Triggered by the energy-warning events, the miniaturised Tyndall 10mm data collector nodes adaptively and periodically change their association to 25mm base station nodes, while 25mm nodes also change the inter-connections between themselves, which results in reconfiguration of the 25mm nodes tier topology. The distributed routing protocol uses combined weight functions to balance the sensor network traffic. A system level simulation is used to quantify the benefit of the route management framework when compared to other state of the art approaches in terms of the system power-saving.