# PhD defence by Mohsen Barforooshan

## Time

16.01.2019 kl. 12.30 - 16.00

## Description

Title
Trade-Offs between Performance, Data Rate and Transmission Delay in Networked control Systems

Abstract
Communication uncertainties caused by phenomena such as time delay, data rate limitation and data packet dropout insert new constraints which should be addressed very carefully when analyzing and designing networked control systems (NCSs). Otherwise, those imperfections may have adverse impacts on system performance.

In this thesis, we study trade-offs between communication constraints and control performance in NCSs. The work encompasses two research directions. One deals with establishing bounds on the infimum data rate required to attain a prescribed quadratic performance level in an NCS with channel-induced delay by using the information-theoretic properties of causal feedback loops. The other utilizes arguments in hands-off control in two setups.

The first setup is a packetized predictive control system closed over a channel subject to time delay and data packet dropouts where conditions for stabilizing the system by sparse control inputs are derived.

The last one is the LQR-constrained $\ell^1$-optimal control of linear systems subject to discrete and polytopic model uncertainties.

Assessment Committee
Professor Rafal Wisniewski, Aalborg University, Denmark (Chairman)
Professor Tobias Oechtering, KTH Royal Institute of Technology in Stockholm
Professor Nuno Martins, University of Maryland

Supervisor
Professor Jan Østergaard, Aalborg University, Denmark

Moderator
Head of Section Peter Koch, Aalborg University, Denmark

After the defence there will be a reception at Fredrik Bajers Vej 7, B4-211

Free of charge

### Host

Signal and Information Processing, Department of Electronic Systems