A robust test of uncertain linear systems

In this paper, it is shown that for low-order uncertain systems, there is no need to calculate all the minimum and maximum values of the coefficients for a perturbed system which is expressed in terms of polynomials and hence no need to formulate and test all the four Kharitonov’s polynomials. Furthermore, for higher-order systems such as n ⩾ 5, the usual four Kharitonov’s polynomials need not be tested initially for sufficient condition of perturbed systems; rather, the necessary condition can be checked before going for sufficient condition. In order to show the effectiveness of the proposed method, numerical examples are shown and computational efficiency is highlighted. Yogesh V. HOTE received his B.E. degree in Electrical Engineering from Govt. College of Engineering, Amravati in 1998. Then, he received his M.E. degree in Control Systems, from Govt. College of Engineering, Pune, in 2000. Since 2001, he has been associated with the Netaji Subhas Institute of Technology (NSIT), New Delhi. Currently, he holds the post of Sr. Lecturer, in the Instrumentation and Control Department. His field of research includes robust control, robotics, numerical analysis and power electronics. D. Roy CHOUDHURY received his B.Tech. and M.Tech degrees in Radio Physics and Electronics from the Institute of Radio Physics and Electronics, University of Calcutta, Calcutta in 1965 and 1966, respectively. He was awarded the degree of Doctor of Philosophy from the same university in 1971. From 1971 to 1973, he was associated with the Institute de Reglage Auto-matique, Ecole Polytechnique Federale de Lausanne, Switzerland. Since 1974, he has been associated with Delhi College of Engineering, Delhi. Currently, he holds the post of Professor in Computer Science Department, University of Delhi. His field of research includes control systems, digital communications, and biomedical engineering. J. R. P. Gupta received his B.S. (Engg.) degree in Electrical Engineering from Muzaffarpur Institute of Technology, Muzaffarpur, and his Ph.D. from University of Bihar in 1972 and 1983, respectively. After serving in the Post and Telegraph Department, Government of India for nearly three years, he joined Muzaffarpur Institute of Technology (MIT) as Assistant Professor in the Electrical Engineering Department in 1976. He then switched over to the Regional Institute of Technology, Jamshedpur in 1986 and then to the Netaji Subhas Institute of Technology (NSIT), New Delhi in 1994 where currently he holds the post of Professor and Head of the Instrumentation and Control Engineering Department of University of Delhi. His research interests include power electronics, electrical drives, power quality assessment of electrical power systems, control theory, intelligent instrumentations, etc. He was awarded the K.S. Krishnan Memorial Award for the best system-oriented paper by the Institute of Electronics and Telecommunication Engineers (India), in 2008.