Curriculum  Vitae  di  Elio USAI

¾Main Information¾

Current Position

Associate Professor of the Automatic Control Group at the Department of Electrical and Electronic Engineering , University of Cagliari, since October 2000.

Previous Positions

Ø     Process Engineer for telecommunication cables at the Department for Research and Technical Development, Labs in Milan, Pirelli Cavi S.p.A.,  from June 6th 1987 to September 30th 1988.

Ø     Process Engineer for Auxiliary Services at the  EniChem factory in Porto Torres from October 10th 1988 to 1990.

Ø     Production manager for Auxiliary Services at the  EniChem factory in Porto Torres from 1990 to September 11th 1994.

Ø     Assistant Professor of the Automatic Control Group at the Department of Electrical and Electronic Engineering , University of Cagliari, from September 12th 1994 to September 30th 2000.

Education

Laurea with honours (five year course) in Electrical Engineering at the University of Cagliari on April 12th 1985. Thesis on “Time optimal control of forest systems”.

Activities

a)      Research  activity

Current and past research topics:

Ø     Variable Structure Systems

The main goal of the research work is to attenuate and limit significantly the problems due to the use of a discontinuous control for compensate for matched uncertainty and disturbance. Some techniques for the adaptation of the switching control has been proposed and an original control law for relative degree two, implementing a second order sliding mode, was developed. For such a control law the robustness with respect to digital implementation and measurement noise have been analysed. Furthermore, its generalization to achieve general convergence properties was proposed.

Current research is focused on the analysis of the steady-state accuracy, and on the design of proper control schemes to improve it, in the presence of unmodelled dynamics of both sensors and actuators.

Ø     Robust observers

A non-linear observer that does not need any preliminary transformation of the system model has been proposed exploiting some structural properties and the higher-order sliding mode approach. The analysis of the influence of model mismatching was carried out, and sufficient conditions for strong observability were derived.

Current research is focused on the extension to multi-variable and to hybrid systems of the proposed observation scheme. Furthermore, applications to fault diagnosis are currently analysed.

Ø     Robust Output-feedback of non-linear systems

The use of real-time differentiators allows for the implementation of robust output-feedbach control schemes for non-linear systems. The main problem is that of the measurement noise that influence the performance of the overall control system. Comparative analysis, and development of new differentiation algorithms is the basis for the effective implementation of various output-feedback schemes proposed in the literature.

The analysis of the effects of digital implementation (sampling and truncation) and simple tuning rules are currently under study.

Ø     Control of mechanical systems

The possible advantages of the application of robust control techniques via sliding modes to mechanical systems have been, and are, considered for the control in the presence of uncertainty. In particular the regulation of the contact force in high-speed trains, the hybrid control of robotic manipulators, the trajectory control and oscillation damping in overhead cranes, and the jet propulsion for ROV were dealt with. In the latter two problems experimental test on laboratory sized prototypes were successfully carried out.

Ø     Control and synchronisation of chaotic systems

The use of real-time differentiators allows for the implementation of effective algebraic observers for the state reconstruction, and under proper conditions of the unknown input as well, in chaotic systems. Furthermore, suitable controllers can be designed based on sliding mode differentiators and controllers. Successful tests on a Chua's circuit were carried out.

Ø     Modelling of hybrid systems

A formal model for modelling hybrid systems was proposed. Even if the model seems to be interesting from a methodical point of view, its complexity makes hard its use in applications. 

Ø     Parameters identification in non-linear systems

Numerical methods to identify the system parameters of non-linear dynamical systems from historical data were developed. The proposed algorithms have been verified on the growth data of a forest. This topic was strictly related to the Laurea thesis and give rise to some numerical codes for optimal control problems, based on shooting methods.

b)     Teaching at University of Cagliari

Ø     Professor in various classes of automatic control and process control at the Faculty of Engineering.

Ø     Tutor of several final thesis of students of the first and second level courses in Electrical Engineering, Electronic Engineering, Mechanical Engineering, on topics related to the theory and applications of automatic control systems. Some thesis were carried out in cooperation with industries in Sardinia. 

Ø     Tutor of some students of the PhD courses in Electronic Engineering and Computer Science, and in Industrial Engineering.

c)      Other teaching activities

Ø     Lecturer in several courses on process control for technical personnel at the industry.

Ø     Lecturer at the Summer School on “ODEs with Discontinuous Right-Hand Side: Theory and Applications”, Dobbiaco, Italy, June 22-26, 2009.

d)     Scientific and professional commitment with industries

Ø     SECrET project (Effective Systems for cryptography via chaotic time series), F.S.T. Gruppo Atlantis (Cagliari)- Project leader: prof. S. Cincotti (DIBE, Università di Genova). (1999).

Ø     Project on “Development of a positioning control device for the actuator of control valves in gas and steam turbines”,  Ansaldo Energia - Gruppo Finmeccanica (Genova). Project leader: prof. G. Bartolini (DIEE, Università di Cagliari). (2005).

Ø     Project on “Technical and scientific support, preliminary project of the process control systems for a small-sieze solar power plant”, Elianto S.r.l. (2007-08).

e)                  Management at the University of Cagliary

Ø     Manager of the Automatic Control Laboratory at the Department of Electrical and Electronic Engineering, since March 28th, 2000.

Ø     Coordinator of the Technological curricula at the S.I.S.S. (Specialization School for High-School Teachers) Sardegna, Section of Cagliari, since December 2003.

Ø     Secretariat of the Electronic Engineering Curricula at the Faculty of Engineering, from October 2000 to September 2006.

Ø     Coordinator of the Electronic Engineering Curricula at the Faculty of Engineering, since October 2006.

f1)                  Coordination of research projects

Ø     2002: R.A.S. (Regional Administration of Sardinia), funding of a research grant on “Implementation of advanced control techniques on distributed control systems (D.C.S)”.

Ø     2003: R.A.S. (Regional Administration of Sardinia), funding of an international cooperative project on “Singular perturbations in variable structure control systems in the presence of unmodeled dynamics of sensors and actuators”. Partner: U.N.A.M. (Universidad National Autonoma de Mexico).

Ø     2003: University of Cagliari – Local Research Projects (2002-03), “Advanced control methods for uncertain and hybrid systems”.

Ø     2003: University of Cagliari –  (Research grant co-funded by Consorzio 21) – “Modelling, supervision and control of not conventional robotic systems”.

Ø     2004: Hydrocontrol, “Effective localization of actuation and measurement devices in pressurised water distribution networks” .

Ø     2004-2005: MIUR (Italian Ministry for Research and University), “Robust regulation in active pantographs via variable structure controllers”, sub-project of the PRIN “Improving the current collection in high speed trains by means of active pantographs and remote diagnosis”, national project leader:  Prof. A. Landi (University of Pisa)

Ø     2006: University of Cagliari –  (research grant funded by Consorzio COSMOLAB) – “Modelling, control and supervision of gantry cranes”.

Ø     2007-2009: MAE (Italian Ministry for Foreign Affairs) - 2nd program for scientific and technological cooperation between Itay and Mexico. “Sliding mode observers for the estimation of disturbances and state variables in uncertain systems”. Partner: U.N.A.M. (Universidad National Autonoma de Mexico).

Ø     2008-2010: EC-FP7 (European Community, 7th Framework Program), “Robust model-based FDI for power plants”, sub tasks of the project  Complex Power plants RObustification by fault Diagnosis, Isolation and Advanced Control Techniques (PRODI)”, Coordinator Prof. Zeljko Djurovic (University of Belgrade).

f2)    Member in other research projects

Ø     1995-2008: Several national and local research projects under the ledership of colleagues of the Automatic Control Group at the DIEE.

Ø     2005-2009: research unit on “Advanced control techniques for combined-cicle power plants” of the National project “New models and techniques for the control, diagnosis, and management of combined-cicle power plants in highly perturbed conditions”, funds from the Italian Ministry for Research and University and University of Cagliari, coordinator for the University of Cagliari prof. G. Bartolini.

Ø     2007-2010: research unit on “Study, development and design of the supervision and control systems” of the National project “Laboratory for the development of technology for high temperature solar power plants”, funds from the Italian Ministry for Research and University of Cagliari, coordinator for the University of Cagliari prof. G. Cau.

g)     Scientific events

Ø   Member of the Local Comittee  of the 4th Int. Workshop on Discrete Event Systems (WODES'98), Cagliari, Italy, August 1998.

Ø   Organizer/Co-organizer of various special sessions in international conferences

Ø   Member of the International Program Committee of the  2nd IFAC conference on the Analysis and Design of Hybrid Systems (ADHS'06), Alghero, Italy, June 2006.

Ø   General Chairperson of the 9th Int. Workshop on Variable Structure Systems (VSS’06), Alghero, Italy, June 2006.

Ø   Invited speaker at the 5th Workshop on Structural Dynamical Systems: Computational Aspects (SDS'08), Capitolo (BA), Italy, June 2008.

Ø   Member of the International Program Committee of the  11th Int. Workshop on Variable Structure Systems (VSS’10), Mexico City, Mexico, June 2010.

h)        Editing and publications

Ø   Reviewer for several international journal on Automatic Control.

Ø   Associate Editor of the Asian journal of Control since November 2008.

Ø   Co-editor of the book: Bartolini G., Fridman L., Pisano A., Usai E., editors, Modern Sliding Mode Control Theory – New Perspectives and Applications, Lecture Notes in Control and Information Sciences, LNCIS 375, ISBN 978-3-540-79015-0, Springer-Verlag, Berlin, 2008.

Ø   Co-author of more that 100 articles on international journals and conferences with review.

i)         Professional

Ø     Process engineer in international companies, with specific work on production technologies and electrical networks

Ø     Production manager of the auxiliary plants (power plant, air distillation, demineralised water, compressed technical fluids and energy distribution networks) at the EniChem petrochemical factory in Porto Torres.

j)         Awards

Ø    “Best paper award”, in the symposium Chaos, Anticipation and Mathematical Systems at CASYS 2000, for the paper “Chaos synchronisation via Sliding Modes”, authors: Barbara CANNAS, Silvano CINCOTTI ed Elio USAI.