Non-fragile control for UMH with pole constraints

This paper investigates the problem of robust and non-fragile H-infinity control for unmanned helicopter (UMH). Model uncertainty and gust disturbance are simultaneously exist. A robust and non-fragile H-infinity control scheme based on output feedback is presented against this problem, and a control system is designed for the linearized mode of UMH. The closed-loop system is asymptotical stable and meets the demands of H-infinity capability with respect to mode uncertainty and control system gain perturbations. The closed-loop poles are assigned in a specific disk region on the complex plane as well. Additive perturbations are considered. Solvability condition for the existence of robust and non-fragile control system is derived in the form of a linear matrix inequality (LMI). Finally, this method is applied to an UMH's longitudinal motion control, which also demonstrates the effectiveness of the proposed approach.