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

摘要

This paper presents procedures to handle time delays in a feedbackncontrol loop in which both measurement and control signalsnare sent through a network, where random time delays occur.nEven when time stamps are utilized, for example, the control signalntime delay still must be estimated. Using a Padé approximationnand a Kalman filter, we can estimate the mean time delay.nFurthermore, methods are described to estimate the time delay ofnevery packet instead of the mean for the measurement channel,nwhich greatly enhances the performance of the Padé approximationnapproach. This is done by matching the measurements to thenexpected measurements provided by the filter with maximum likelihood.nThe methods are applied to an inverted pendulum to assessnperformance.