Static interpolated ℋ∞ loop-shaping controllers for missile autopilot synthesis

This paper presents a systematic methodology in order to compute a nonlinear gain-scheduling controller for a missile autopilot. A nominal control is first calculated using an output-based equilibrium analysis of the system so as to properly track reference trajectories. A closed loop controller is then calculated as an interpolation of LTI static controllers to complement the nominal controller. These LTI controllers are computed on a small number of the plant´s equilibrium points. The form of every local LTI controller is a cascaded one, namely an internal/external P/PI controller followed by an Hscr_infin loop-shaping static controller. The interpolation is performed according to the scheduling vector, which in this case is composed of the plant´s output and Mach number. The results are motivated by the need for a predetermined-simple structure gain-scheduled control scheme, in order for it to be easily implemented and tractable on a real world application.