Speaker: Dr. Tamer Basar, University of Illinois at Urbana-Champaign

Thursday, February 9, 2017  |  12:30 PM CST

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Abstract

The paradigm of networked control systems, where the feedback loop is closed over heterogeneous networks, has opened up a vast number of opportunities for applications in different fields while creating also a number of challenges with regard to reliability, robustness, and security of control operations. This talk will address these challenges, where networks providing sensor measurements to controller(s) and those carrying control signals to the plant as well as the plant itself are vulnerable to stochastic as well as adversarial disturbances and sporadic failure of channel connectivity. The question of interest is the extent to which the plant, measured in terms of a performance metric, can tolerate such disturbances and failures, which themselves are also quantified in terms of some appropriate metrics.

Following a general overview of networked control problems, the talk will focus on linear-quadratic systems, with norm-bounded deterministic (adversarial) disturbance inputs and hybrid stochastic uncertainty, both of which impact network channels, where the latter is characterized by additive Gaussian noise and Bernoulli type failures. Explicit results for both the estimation problem and the control problem will be discussed under the TCP (Transmission Control Protocol) type information structure (which leads to certainty-equivalance, but not to separation of estimation and control), and the trade-offs between control performance, disturbance energy, and channel failure rates (that is, channel reliability) will be quantified. Under the UDP (User Datagram Protocol) type packet loss acknowledgement process, on the other hand, there is no certainty-equivalance, but still some trade-off results can be obtained. The talk will conclude with a discussion of future directions of research in this topical area and the challenges that lie ahead.

Biography