Aleksandar Stankovic, Masoud Salehi
Date of Award
Master of Science
Department or Academic Unit
College of Engineering, Department of Electrical and Computer Engineering
electrical engineering, communication delay, communication network, distributed sensing, feedback control, irregular sampling, Kalman filter
Signal processing, Estimation theory
Electrical and Computer Engineering | Engineering
Motivated by distributed control and sensor network applications in Electric Energy Systems, we consider the problem of estimation via a communication network. When data is sent via communication channels in a large, wireless, multi-sensor network, the effect of communication constraints on estimation performance, such as communication delay and asynchronous irregular sampling, have to be considered. In this thesis we formulate a delay mitigation method based on a Kalman filter with time-stamping technology, which transmutes communication delay into increased estimation error, so that the closed-loop control system remains stable even in the presence of significant delay. The resulting signal to estimation error ratio (SEER), at any point in the estimation-control loop, is a monotone decreasing function of the average communication delay. When the sensor sampling patterns (SSP) are irregular and asynchronous, the SEER is a monotone decreasing function in each one of the average sampling intervals, with very minor dependence on higher order moments of this interval. The best performance is achieved when the individual SSPs are regular and aligned in such a way that the superposed set of sampling instants is as close to regular as possible. In particular, synchronized regular sampling (i.e., all sensors sampled regularly at the same time instants) is inferior to uniformly staggered regular sampling, in which the sampling instants of individual sensors are spaced evenly within a single sampling interval.
Yan, Bei, "Estimation and control under communication network constraints" (2010). Electrical and Computer Engineering Master's Theses. Paper 52. http://hdl.handle.net/2047/d20000949
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