Hybrid Micropower Supply for Wearable-Pervasive Sensor nodes

Lee

International Journal of Human-Computer Interaction

2009

Smart clothing is a "smart system" capable of sensing and communicating with environmental and the wearer's conditions and stimuli. A comprehensive review is presented on the research and developments related to smart clothing including technology developments, human aspects in smart clothing, and the applications. Recent smart clothing technology can be summarized as a tendency toward textilebased technology for each component: interface, communication, data management, energy management, and integrated circuits. Human aspects in smart clothing, even though some areas were not fully covered, were dealt with in terms of usability, functionality, durability, safety, comfort, and fashion. General applications of smart clothing developed so far include bio-monitoring clothing, MP3 player-adopted clothing, and photonic clothing.

Section: Energy Management Technologiesmentioning

confidence: 99%

Review and Reappraisal of Smart Clothing

Lee

International Journal of Human-Computer Interaction

2009

“…This vision implies that the sensor nodes should be extremely small and consume so little power that no power source change is required for several years or months. Working towards this vision, the previous work of our group has dealt with issues such as: activity recognition using low-power features and classifier algorithms [4; 5]; optimization of power and size in a multi-sensor context recognition platform [6]; development of micro hybrid power supply to achieve autonomous behaviour [7]; electronic packaging aspects of an ultra miniaturized sensor button [8]; and architectural tradeoffs in wearable systems [9]. A figure of merit to study the design trade offs by three metrics; functionality (depends on the recognition performance), power consumption, and electronic packaging is also proposed [10].…”

Section: Related Workpaper Scopementioning

confidence: 99%

On-Body Context Recognition with Miniaturized Autonomous Sensor Button (Situationserkennung mit am Körper getragenen autonomen Minisensoren)

Bharatula¹,

Tröster²

2007

Teme

The vision of wearable computing is a personal mobile system that is always "on" and always useful and unobtrusive. In this article we present the on-body context recognition analysis considering the functionality or recognition performance, power, and packaging. Interaction with household appliances using a wrist worn "autonomous sensor button" is analyzed as a case study. An overall on-line recognition performance between 85 and 91% is reported. The measured power consumption of the sensor button at 10% duty cycle is around 500 µW. The power profiling in an office worker daily life scenario shows that it's possible to achieve autonomous operation by a solar cell having an area of 40 cm 2 . Situationserkennung mit am Körper getragenen autonomen MinisensorenDie Vision eines tragbaren Computers besteht aus einem PDA, der ständig eingeschaltet, ständig nutzbringend und trotzdem nicht aufdringlich ist. In diesem Beitrag stellen wir ein System zur Situationserkennung vor und betrachten Funktionalität, Erkennungsqualität, Leistungsverbrauch und Gehäusung. Das Zusammenwirken mit Hausgeräten, unter Verwendung eines am Handgelenk getragenen autonomen Sensorknopfes, wird als Fallstudie behandelt. Eine Gesamt-Online-Erkennungsrate zwischen 85 und 91% wird erreicht. Der gemessene Leistungsverbrauch eines Sensorknopfes beträgt bei einem Tastverhältnis von 10% etwa 500 µW. Das Leistungsprofil in einem für Büroangestellte üblichen Szenario zeigt, dass es möglich ist, einen autonomen Betrieb mit einer Solarzellenfläche von 40 cm 2 sicherzustellen.

“…This vision implies that the wearable sensor nodes should be extremely small and consume so little power that no power source change is required for several months to years. Working towards this vision, the previous work of our group dealt with issues such as, activity recognition using low-power features and classifier algorithms [4,6], optimization of power and size in a multi-sensor context recognition platform [7], development of hybrid micro power supply to achieve autonomous behavior [8], electronic packaging aspects of an ultra-miniaturized wearable sensor button, reliability modeling of embedded systems in wearable computing [9,10], detailed systematic approach considering wearability and power consumption [11] and methodologies for context-aware system design were proposed [12] for selecting optimized architectures with respect to power consumption. The main aspect which sets us aside from the work done by other groups in the field of personal and ubiquitous systems is the focus on context aware wearable systems.…”

Section: Related Work and Paper Contributionmentioning

confidence: 99%

Functionality-power-packaging considerations in context aware wearable systems

Bharatula

Lukowicz

Tröster

2006

Pers Ubiquit Comput

Wearable computing places tighter constraints on architecture design than traditional mobile computing. The architecture is described in terms of miniaturization, power-awareness, global low-power design and suitability for an application. In this article we present a new methodology based on three different system properties. Functionality, power and electronic Packaging metrics are proposed and evaluated to study different trade offs. We analyze the trade offs in different context recognition scenarios. The proof of concept case study is analyzed by studying (a) interaction with household appliances by a wrist worn device (acceleration, light sensors) (b) studying walking behavior with acceleration sensors, (c) computational task and (d) gesture recognition in a wood-workshop using the combination of accelerometer and microphone sensors. After analyzing the case study, we highlight the size aspect by electronic packaging for a given functionality and present the miniaturization trends for 'autonomous sensor button'.Keywords Wearable computing Á Context recognition Á Gesture Á Electronic packaging Á Functionality Á Miniaturization Context aware wearable systemsWearable computing as defined by [1, 2] envisions personal, mobile computing systems that are always on, useful in all situations and most of all, easy to use. Thus whereas a conventional mobile device would only be used for an occasional schedule check or address lookup, a wearable device would constantly provide the user with useful information such as nearby shops and special offers, transport delays, or health and lifestyle-related reminders (taking medicine, diet etc). Such systems are particularly important in professional applications such as emergency response units, manufacturing and maintenance. Thus a wearable system might constantly provide a fireman with hints and warning about hazards related to his environment, his physiological state and his current actions.A key component of the wearable computing vision is the ability of the system to model and recognize user activity and the situation around him. This so called context awareness [3] allows the system to proactively provide the user with the right information at the right time, reduces the complexity of the user interface, and allows new modes of information recording. One of the most popular approaches to context awareness in a mobile environment is based on simple on-body sensors. Thus an accelerometer, light sensor and a microphone placed on the wrist could be used to track interaction with household appliances [4] or the use of tools [5]. In a similar way an accelerometer and/or gyroscope on the upper leg can differentiate between level walking, going upstairs, going downstairs and running.