Robust synthesis in /sub 1/ via /spl mu/ approach and D-K iteration [Space Shuttle example]

In this paper, we propose the linear fractional transformation (LFT) method to synthesize controllers that achieve globally robust stability, robust performance, and satisfactory worst-case performance, within any prescribed tolerance, against structured norm-bounded time-varying and/or nonlinear uncertainty, respectively. The uncertainty is characterized by any prescribed tolerance, against structured norm-bounded time-varying and/or nonlinear behaviors. The output feedback synthesis problem when the signal norm is proposed to get the /sub /spl infin// norm and the perturbations are structured time-varying and/or nonlinear systems with an induced /spl infin/-norm bound. A global optimal solution to the robust synthesis problem is obtained. A synthesizing /sub 1/ controller for a simplified space-shuttle model is taken from the /spl mu/-analysis and D-K iteration method to compare each other.