TY - GEN
T1 - Tragedy of the coulombs
T2 - 13th ACM Conference on Embedded Networked Sensor Systems, SenSys 2015
AU - Hester, Josiah
AU - Sitanayah, Lanny
AU - Sorber, Jacob
N1 - Funding Information:
The authors would like to thank the members of the PERSIST lab, for helpful discussions around UFoP deployments and experimentation. We also thank our shepherd Kay R?mer, and our anonymous reviewers, for their helpful comments. This research is based upon work supported by the National Science Foundation under grants ACI-1212680 and CNS-1453607. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation
PY - 2015/11/1
Y1 - 2015/11/1
N2 - Untethered sensing devices have, for decades, powered all system components (processors, sensors, actuators, etc) from a single shared energy store (battery or capacitor). When designing batteryless sensors that are powered by harvested energy, this traditional approach results in devices that charge slowly and that are more error prone, inflexible, and inefficient than they could be. This paper presents a novel federated approach to energy storage, called UFoP, that partitions and prioritizes harvested energy automatically into multiple isolated smaller energy stores (capacitors). UFoP simplifies task scheduling, enables efficient use of components with differing voltage requirements, and produces devices that charge more quickly under identical harvesting conditions than a traditional centralized approach. We have implemented a UFoP reference design and conducted extensive experimental evaluation, including a short deployment. Our experimental results using an MSP430-based prototype show that UFoP provides as much as 10% more computational availability, and as much as four times more radio availability than the centralized approach. For all applications and energy environments evaluated, UFoP harvested 0.7-10.2% more energy than the centralized equivalent; meaning UFoP adds zero energy overhead.
AB - Untethered sensing devices have, for decades, powered all system components (processors, sensors, actuators, etc) from a single shared energy store (battery or capacitor). When designing batteryless sensors that are powered by harvested energy, this traditional approach results in devices that charge slowly and that are more error prone, inflexible, and inefficient than they could be. This paper presents a novel federated approach to energy storage, called UFoP, that partitions and prioritizes harvested energy automatically into multiple isolated smaller energy stores (capacitors). UFoP simplifies task scheduling, enables efficient use of components with differing voltage requirements, and produces devices that charge more quickly under identical harvesting conditions than a traditional centralized approach. We have implemented a UFoP reference design and conducted extensive experimental evaluation, including a short deployment. Our experimental results using an MSP430-based prototype show that UFoP provides as much as 10% more computational availability, and as much as four times more radio availability than the centralized approach. For all applications and energy environments evaluated, UFoP harvested 0.7-10.2% more energy than the centralized equivalent; meaning UFoP adds zero energy overhead.
KW - Capacitor
KW - Embedded system
KW - Energy harvesting
KW - Federated energy
KW - Task coupling
UR - http://www.scopus.com/inward/record.url?scp=84962800245&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84962800245&partnerID=8YFLogxK
U2 - 10.1145/2809695.2809707
DO - 10.1145/2809695.2809707
M3 - Conference contribution
AN - SCOPUS:84962800245
T3 - SenSys 2015 - Proceedings of the 13th ACM Conference on Embedded Networked Sensor Systems
SP - 5
EP - 16
BT - SenSys 2015 - Proceedings of the 13th ACM Conference on Embedded Networked Sensor Systems
PB - Association for Computing Machinery, Inc
Y2 - 1 November 2015 through 4 November 2015
ER -