Towards cyber-physical systems in social spaces: The data reliability challenge

Shiguang Wang, Dong Wang, Lu Su, Lance Kaplan, Tarek F. Abdelzaher

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


Today's cyber-physical systems (CPS) increasingly operate in social spaces. Examples include transportation systems, disaster response systems, and the smart grid, where humans are the drivers, survivors, or users. Much information about the evolving system can be collected from humans in the loop, a practice that is often called crowd-sensing. Crowd-sensing has not traditionally been considered a CPS topic, largely due to the difficulty in rigorously assessing its reliability. This paper aims to change that status quo by developing a mathematical approach for quantitatively assessing the probability of correctness of collected observations (about an evolving physical system), when the observations are reported by sources whose reliability is unknown. The paper extends prior literature on state estimation from noisy inputs, that often assumed unreliable sources that fall into one or a small number of categories, each with the same (possibly unknown) background noise distribution. In contrast, in the case of crowd-sensing, not only do we assume that the error distribution is unknown but also that each (human) sensor has its own possibly different error distribution. Given the above assumptions, we rigorously estimate data reliability in crowd-sensing systems, hence enabling their exploitation as state estimators in CPS feedback loops. We first consider applications where state is described by a number of binary variables, then extend the approach trivially to multivalued variables. The approach also extends prior work that addressed the problem in the special case of systems whose state does not change over time. Evaluation results, using both simulation and a real-life case-study, demonstrate the accuracy of the approach.

Original languageEnglish (US)
Title of host publicationProceedings - IEEE 35th Real-Time Systems Symposium, RTSS 2014
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages12
ISBN (Electronic)9781479972876
StatePublished - Jan 14 2015
Event35th IEEE Real-Time Systems Symposium, RTSS 2014 - Rome, Italy
Duration: Dec 2 2014Dec 5 2014

Publication series

NameProceedings - Real-Time Systems Symposium
ISSN (Print)1052-8725


Other35th IEEE Real-Time Systems Symposium, RTSS 2014

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Computer Networks and Communications


Dive into the research topics of 'Towards cyber-physical systems in social spaces: The data reliability challenge'. Together they form a unique fingerprint.

Cite this