Non-fragile static output feedback control design with guaranteed cost of uncertain systems with application to helicopter system

The paper is concerned with non-fragile control design via output feedback controller for uncertain systems. In control design for physical systems, there are chances that malfunction in actuator happens and an exact value of the control input may not be applied. Hence controller gain variations should be considered in the control design. Additionally, many results on the state feedback control design have been given in the literature. However, in the actual situation, the state of the system is not always measured and the output feedback control design is desired. In this paper, non-fragile guaranteed cost control via output feedback control for uncertain systems is considered and a control design of stabilizing controllers with guaranteed cost and robustness against uncertainties of system parameters and control gains is proposed. The robust stability analysis of the closed-loop system and controller design are given in terms of LMI conditions, which are less conservative than the existing results.