Experiences with eNav: A low-power vehicular navigation system

Shaohan Hu, Lu Su, Shen Li, Shiguang Wang, Chenji Pan, Siyu Gu, Md Tanvir Al Amin, Hengchang Liu, Suman Nath, Romit Roy Choudhury, Tarek F. Abdelzaher

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents experiences with eNav, a smartphonebased vehicular GPS navigation system that has an energysaving location sensing mode capable of drastically reducing navigation energy needs. Traditional navigation systems sample the phone's GPS at a fixed rate (usually around 1Hz), regardless of factors such as current vehicle speed and distance from the next navigation waypoint. This practice results in a large energy consumption and unnecessarily reduces the attainable length of a navigation session, if the phone is left unplugged. The paper investigates two questions. First, would drivers be willing to sacrifice some of the affordances of modern navigation systems in order to prolong battery life? Second, how much energy could be saved using straightforward alternative localization mechanisms, applied to complement GPS for vehicular navigation? According to a survey we conducted of 500 drivers, as much as 91% of drivers said they would like to have a vehicular navigation application with an energy saving mode. To meet this need, eNav exploits onboard accelerometers for approximate location sensing when the vehicle is sufficiently far from the next navigation waypoint (or is stopped). A user test-study of eNav shows that it results in roughly the same user experience as standard GPS navigation systems, while reducing navigation energy consumption by almost 80%. We conclude that drivers find an energy-saving mode on phone-based vehicular navigation applications desirable, even at the expense of some loss of functionality, and that significant savings can be achieved using straightforward location sensing mechanisms that avoid frequent GPS sampling.

Original languageEnglish (US)
Title of host publicationUbiComp 2015 - Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing
PublisherAssociation for Computing Machinery, Inc
Pages433-444
Number of pages12
ISBN (Electronic)9781450335744
DOIs
StatePublished - Sep 7 2015
Event3rd ACM International Joint Conference on Pervasive and Ubiquitous Computing, UbiComp 2015 - Osaka, Japan
Duration: Sep 7 2015Sep 11 2015

Publication series

NameUbiComp 2015 - Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing

Other

Other3rd ACM International Joint Conference on Pervasive and Ubiquitous Computing, UbiComp 2015
CountryJapan
CityOsaka
Period9/7/159/11/15

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Keywords

  • Dead-reckoning
  • GPS
  • Low-power
  • Navigation
  • Smartphone

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Hardware and Architecture
  • Software

Cite this

Hu, S., Su, L., Li, S., Wang, S., Pan, C., Gu, S., Amin, M. T. A., Liu, H., Nath, S., Choudhury, R. R., & Abdelzaher, T. F. (2015). Experiences with eNav: A low-power vehicular navigation system. In UbiComp 2015 - Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing (pp. 433-444). (UbiComp 2015 - Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing). Association for Computing Machinery, Inc. https://doi.org/10.1145/2750858.2804287