H_∞ Loop Shaping Using Polytopic Weights and Pole Assignment to Missile Autopilot

Modern missiles must deal with stringent performance requirements and ensure robustness across a wide range of operating conditions during flight time. Classic gain-scheduling designs have been successful in practice, but do not provide theoretically ensured bounds on both robustness. Controllers are interpolated at intermediate switching them may cause instability. On the other hand, polytopic linear parameter-varying (LPV) controllers avert this use real-time information about plant, order to smooth out gain scheduling. We hereby propose novel procedure yield an output feedback LPV controller that ensures robust $\text{H}_{\infty} $ missile longitudinal autopilot. Our approach considers four-block loop-shaping control theory weights coordinates plant. One is capable adjusting singular values open-loop plant individually polytope vertices, benefits from trade-off between matrix inequalities (LMI) based optimization tools designer experience. This can be construed as natural extension traditional method uses time-invariant (LTI) weights. Assuming scheduling variables frozen, we also include LMI for assigning closed-loop poles hence circumvent reduction. Nonlinear simulations assess proposed autopilot, results show improved stability margin, addition response acceleration command, concerning LTI-based approach.