Abstract: It is well known that the variable structure control is now recognized as one of the powerful robust tools for solving control problems of uncertain linear and nonlinear dynamical systems subject to parameter perturbations, unmodeled dynamics, external disturbances, and time-delay effects.
Several fundamental monographs and books have been written on the various aspects of the variable structure control and time-delay systems, and their world wide applications in various industrial and manufacturing systems since 1960’s. Recent advances and some new results on the stability analysis and robust sliding mode control of multivariable uncertain dynamical systems with and without time-delay are systematically presented in this survey. The materials of this survey are original, which are obtained by the author in the past decade in Istanbul Technical University. The survey is not only a collection of the authors’ original papers, but also the latest results on variable structure theory and time-delay systems obtained by other authors and colleagues are systematically used in general framework of control theory.
From the brief historical outline of development of variable structure control presented in the survey, it can be seen that significant contributions to the variable structure control has been made by researchers of this control field:
1) Parameters optimization of variable structure control constrained by stability and sliding mode existence conditions
2) Development of new set of pneumatic variable structure P, PI, PID, universal, multistructure, adaptive controllers and systems confirmed by 27 Soviet patents
3) Industrial confirmations and applications of sliding mode controllers with chattering in process control actuated by membrane control valves for the first time.
A key issue in the analysis and design of feedback control systems is the stability and robustness of the resulting closed-loop system. That is the problem of controlling uncertain linear and nonlinear systems without or with time-delay subject to external disturbances is a basic topic that is situated in the center of interest of control researches and engineers. One approach to solving this problem is by using principles and methods of variable structure control.

Brief Biography of the Speaker:
Elbrous Mahmoud Jafarov was born in province Gokche, village Karkibash in the west of Azerbaijan in 15.12.1946 where he left secondary school in 1964 with a gold medal and then he received his first class Honors Degree Electro-Mechanical Engineering Diploma (M.Sc. Degree) in Faculty of Automation of Manufacturing Processes from Azerbaijan Industrial University (now Azerbaijan State Oil Academy) Baku, in 1969. The USSR State Certification of Candidate Eng. Sc. (Ph.D.) and D.Sc. (Eng) degrees from Research Institute NIPINefteKhimAutomat (Sumgait)-TsNIIKAutomation (Moscow)-IMM and Institute of Cybernetics of Azerbaijan Science Academy; and Institute of Control Sciences (Moscow)-MIEM-LETI in Control and Systems Engineering were received in 1973 and 1982 respectively.
He started as a research engineer in NIPINefteKhim-Automat and then he became Head of Variable Structure Control of the Oil-Chemical Process Laboratory from 1969 to 1984. During 1985-1996 he was Chairman of the Control Systems and Robotics Engineering Department at the Azerbaijan Technical University, Baku.
Dr. Jafarov received the USSR State Certification of Professor in Control and Systems Engineering in 1987. He was visiting Professor at Beijing Aeronautical and Astronautical University (BUAA), in 1993, where he was awarded by China State BUAA Advisor Professor Certificate; and Georg-Simon-Ohm-Fachhochule Nurnberg, Germany, in 2001. He has been contractual professor in the Aeronautical and Astronautical Faculty of Istanbul Technical University, Turkey, since 1996. He is a senior student of Islam and Sufism University of Allah, Virginia USA.
Professor Jafarov is the author of the book ’VARIABLE STRUCTURE CONTROL AND TIME-DELAY SYSTEMS’ published by WSEAS Press 2009 and about 200 scientific journal articles, international conference papers, teaching materials, research reports, etc. and 27 Inventions with USSR State Certificates in Control and Systems Practice Engineering. He is a member of IASTED (Canada), WSEAS Academy (Greece), International Technological Cybernetics Academy (Saint Petersburg), Editorial Board of the Open Electrical and Electronic Engineering Journal, Reviewers Board of IEEE Journals and Conferences, Emerald Literati Network (London) etc. His complete biography is included in the Marquis Who’s Who in the World 2006-2009 Editions USA.
His current research and teaching interests include automatic control, variable structure control, time- delay systems, flight dynamics and control, robot control, robust control, optimal control, process control etc. He is also interested in relativity theory, quantum physics, poetry and Sufism. He is married and has two daughters.