Real-time control under clock offsets between sensors and controllers

Kunihisa Okano, Masashi Wakaiki, João P. Hespanha

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

6 Citations (Scopus)

Abstract

This paper studies the impact of clock mismatches in spatially distributed real-time control systems. We consider a configuration in which sensor measurements are collected by one processor that transmits the measurements to another control/actuation processor through a network, but the two processors do not have a common clock. Due to the clock mismatch, there will be an offset between the actual time at which a measurement is taken and the time reported by the sensor. Our goal is to discover fundamental limitations to the ability to stabilize the control loop arising from the clocks mismatch. We consider time-varying bounded offsets and derive limitations on the offset bound for the stability of the feedback system. For the case of a scalar linear process, there exists a critical limitation, which depends on the level of instability of the plant and the nominal sampling period. In contrast, for the vector linear processes, if the process dynamics has at least two distinct real eigenvalues, then there is no fundamental limitation on the offset bound.

Original languageEnglish
Title of host publicationProceedings of the 18th International Conference on Hybrid Systems
Subtitle of host publicationComputation and Control, HSCC 2015
PublisherAssociation for Computing Machinery, Inc
Pages118-127
Number of pages10
ISBN (Electronic)9781450334334
DOIs
Publication statusPublished - Apr 14 2015
Externally publishedYes
Event18th ACM International Conference on Hybrid Systems: Computation and Control, HSCC 2015 - Seattle, United States
Duration: Apr 14 2015Apr 16 2015

Publication series

NameProceedings of the 18th International Conference on Hybrid Systems: Computation and Control, HSCC 2015

Other

Other18th ACM International Conference on Hybrid Systems: Computation and Control, HSCC 2015
CountryUnited States
CitySeattle
Period4/14/154/16/15

Keywords

  • Clock offsets
  • Fundamental limitations
  • Networked control systems

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Computer Science Applications
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

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  • Cite this

    Okano, K., Wakaiki, M., & Hespanha, J. P. (2015). Real-time control under clock offsets between sensors and controllers. In Proceedings of the 18th International Conference on Hybrid Systems: Computation and Control, HSCC 2015 (pp. 118-127). (Proceedings of the 18th International Conference on Hybrid Systems: Computation and Control, HSCC 2015). Association for Computing Machinery, Inc. https://doi.org/10.1145/2728606.2728613