May 23, 2016; h.11:00 - Room 326 DEI/A

Abstract:

Considering the most widely spread configuration of actuators for low orbit satellites, namely a set of reaction wheels and set of magnetorquers, we revisit the classical crossproduct control law solution for achieving attitude stabilization and momentum dumping. We show how the classical solution has a quasi-cascade structure that, under a suitable input-to-state (ISS) stability assumption, is stabilized using an aggressive, thereby making the actuators more inclined to saturate. Motivated by this, we propose a revisited version of this control law that transforms the quasi-cascade into a real cascade. Then, we show that both strategies are such that the attitude control is affected by the momentum dumping, and that they both require a suitable ISS property. To overcome these drawbacks, we propose a new allocation-based controller, which makes the attitude dynamics completely independent of the momentum dumping and induces global asymptotic stability without any ISS requirement. The presented context gives an opportunity to illustrate the features of hybrid feedback for attitude stabilization and a relevant application of hybrid reduction theorems.

Biography:

Luca Zaccarian received the Laurea and the Ph.D. degrees from the University of Roma Tor Vergata (Italy) in 1995 and 2000, respectively. He has been Assistant Professor in control engineering at the University of Roma, Tor Vergata (Italy), from 2000 to 2006 and then Associate Professor. Since 2011 he is Directeur de Recherche at the LAAS-CNRS, Toulouse (France) and since 2013 he holds a part-time associate professor position at the University of Trento, Italy. Luca Zaccarian's main research interests include analysis and design of nonlinear and hybrid control systems, modeling and control of mechatronic systems. He has served in the organizing committee and TPC of several IEEE and IFAC conferences. He has been a member of the IEEE-CSS Conference Editorial Board and an associate editor for Systems and Control Letters. He is currently a member of the EUCA-CEB, an associate editor for the IEEE Transactions on Automatic Control and the IFAC journal Automatica. He was a member of the Board of Governors of the IEEE-CSS in 2014, he has been a senior member of the IEEE since 2009 and he is a fellow of the IEEE since 2016. He is currently Student Activities Chair and Associate Editor of Electronic Publications (Conference Information) for the IEEE-CSS. He was a recipient of the 2001 O. Hugo Schuck Best Paper Award given by the American Automatic Control Council.