General Robust Stability Analysis of Uncertain system

The main objective of this paper is to investigate the robust control aspect of chaotic and uncertain system. The robust stability analysis of closed loop attitude control system of an aircraft is presented using the Kharitonov theorem. The proposed technique for examining the robust stability of chaotic polynomial is efficient and expeditious one as the onerous application of Routh stability criterion for infinite no of interval polynomials of the perturbed system can be completely dispensed with. KeywordsRobust control, Kharitonov’s theorem, Routh criterian, Interval systems Introduction Study and design of robust system has been a matter of concern and drawn the attention of many authors in recent years [1-3]. The designed system is said to be robust if it remains insensitive to the presence of parametric uncertainties. Incorporation of robust features in the modern control design is indispensably necessary. Here, in this paper we take into consideration the example of the precise attitude control of an aircraft which is variedly used in aerospace application. For the precise attitude control of an aircraft we need to control the positions of the fins of a modern aircraft. Fins are mostly the flattened part that projects from an aircraft for providing stability. Owing to the requirement of improved response and reliability, modern aircraft are controlled by electric actuators and electronic control [1]. Initially in order to check the stability of characteristic polynomial by Routh criterion it was assumed that the coefficient of characteristic polynomial are constant but practically it