Robust Gain-Scheduled Control of a UAV Based on a Polytopic Model Approximation

This work addresses the design of a robust H_∞ gain-scheduled controller for the Condor Andino UAV (Unmanned Aerial Vehicle). A polytopic approximation of the linearization family of the nonlinear model is used for the design. Because the linearization family in the operating region derives in a linear parameter varying (LPV) description with a nonlinear dependence of a set of parameters, a least squares approximation of the system matrices is used in order to obtain affine dependence. The polytopic description is obtained from the affine LPV model when the operating range is defined choosing the varying parameter inside a convex hull. The controller is synthesized using the Bounded Real Lemma in order to guarantee quadratic H_∞ performance over the operating region. The simulation results show that the designed controller can be successfully applied to the nonlinear system over the operating range.