Compensating Random Time Delays in a Feedback Networked Control System With a Kalman Filter

TitleCompensating Random Time Delays in a Feedback Networked Control System With a Kalman Filter
Publication TypeJournal Article
Year of Publication2011
AuthorsProbst, A. C., M. E. Magana, and O. Sawodny
JournalJournal of Dynamic Systems, Measurement, and Control
Volume133
Issue2
Pagination024505 (6 pages)
Date Published03/2011
ISSN00220434
Keywordsapproximation theory, delay estimation, delays, feedback, Kalman filters, nonlinear systems, pendulums
Abstract

This paper presents procedures to handle time delays in a feedback control loop in which both measurement and control signals are sent through a network, where random time delays occur. Even when time stamps are utilized, for example, the control signal time delay still must be estimated. Using a Padé approximation and a Kalman filter, we can estimate the mean time delay. Furthermore, methods are described to estimate the time delay of every packet instead of the mean for the measurement channel, which greatly enhances the performance of the Padé approximation approach. This is done by matching the measurements to the expected measurements provided by the filter with maximum likelihood. The methods are applied to an inverted pendulum to assess performance.

DOI10.1115/1.4003094
Short TitleJ. Dyn. Sys., Meas., Control